Remembering the Founding Text of the Animal Rights Movement (not by Peter Singer)

It’s now forty five years since the book of essays Animals, Men and Morals was published. Its editors were three post-graduate philosophers at Oxford, and several of their fellow-writers for the book were likewise University people. Accordingly some of its chapters are academic studies of one kind or another, though written with unacademic fervour and impatience. Others lay out the facts of factory farming, fur and cosmetics, and experiments on animals. Although it made no great splash at the time, this book proved to be the pioneering text for the modern animal rights movement, in both its philosophical and animals-men-morals-coverits political forms. The chapter on vivisection was written by Richard Ryder, then a psychologist in an Oxford hospital, and since that’s the unhappy subject of this blog I shall say a little more about his part in the book.

Ryder himself had done research work with animals (I politely use that richly euphemistic “with”). Therefore he knew the things of which he came to write. What he first wrote was a pamphlet titled Speciesism, which he published and distributed round Oxford in 1970. He had coined its title-word on the analogy of ‘racism’ and ‘sexism’, in order to show at a lexical glance that the moral revolution of the 1960s, unfinished as it obviously was, had still another ancient orthodoxy to start to undo. By placing the subject of animal welfare in a political context in this way, he also freed it from its conventional associations with the minor good works of well-off old ladies (i.e. courageous women who meant to get something right done, as fortunately many still do). When another Oxford post-graduate, Peter Singer, reviewed Animals, Men and Morals for the New York Review of Books, and when he went on to write Animal Liberation (1975), he used ‘speciesism’ as his key word for just those reasons and despite its awkwardness (“the word is not an attractive one, but I can think of no better term”[i]). Defining as it does the essential wrong, Ryder’s word remains a complete work of animal ethics and a rule-book in ten letters.

Singer’s review spoke of Animal, Men and Morals as “a manifesto for an Animal Liberation movement”[ii]. In the event, it was his own book which became that manifesto, and it has been so ever since. But it was the earlier book which had established the proper way to look at the subject: not just as a miscellany of improvised cruelties, calling on the services of kindly people to press for remedies, but as an enormous and systematic wrong requiring a fundamental change of mind. As the book’s ‘Postscript’ says – so much in the spirit of that time, as well as of that project – “we want to change the world.”[iii]

Richard Ryder’s chapter of the book, surveying the law and practice of animal research, was a good deal longer than any of the others. It gives many examples of contemporary experiments, illustrative of what animals might be asked to endure: rats in their ‘Wright Auto-Smoker’, dogs having their legs crushed in the notorious ‘Blalock Press’ (ah, those evocative trade-names!), pregnant baboons in car-crash simulations, and so on. A few of the examples are from Oxford’s laboratories. It’s a disgusting read, and it all sits in the baleful shade of the chapter’s epigraph, taken from the works of one of experimental psychology’s leading practitioners, Harry Harlow: “most experiments are not worth doing and the data obtained are not worth publishing.”[iv]

It is often asked of those who oppose vivisection why they don’t bother about the far greater numbers of animals killed for food. The simple answer of course is that they do. As Animals, Men and Morals insisted, it’s all one subject, though some may specialize within it. But there’s a more unpleasant answer too. Factory farming is itself a product of scientific research. Ruth Harrison showed as much in her chapter of the book, and she had already written, in Animal Machines (1964), that “every batch of animals reaching market is a sequel to another experiment or part of an experiment.” The laboratory may exemplify speciesism in an especially stark and modern way, but it also promotes and facilitates it elsewhere.

A popular account of animal research published in 1963 makes this last point very clearly, and also helpfully illustrates the orthodox thinking of the time. The Science of Animal Behaviour was written for the Pelican imprint by P.L.Broadhurst, a professor at Birmingham. He was presumably aiming the book at the lay-person and the aspiring young scientist, and it is clearly and reasonably intended as an advertisement for his profession. There is not much in it about animals as they can be observed in nature. The laboratory is Broadhurst’s preferred setting, partly because that was his own place of work (rats and the misleadingly fun-sounding “shuttle box” were his customary tools), but mainly because animals in themselves do not quite constitute a subject: “there is essentially only one basic scientific interest in the study of animal behaviour and that is to learn more about man himself.”[v] 

Accordingly, a high point of Broadhurst’s presentation is the contemporary research of that same Professor Harlow into maternal deprivation as it affected baby rhesus monkeys, and therefore might be supposed to concern humans. “Mothers are important, it is generally agreed”, muses our author, himself a family man. “But just how important …?” Harlow’s work with his artificial mothers, carefully graded as to their lovelessness and delinquency, seemed to provide some exciting answers. For instance, as Broadhurst reports, these forlorn babies “preferred a soft cloth model even when it did not provide milk to a hard one which did!” Not just that bumptious exclamation mark, but the cover of the book itself, picturing a monkey in the throes of this pathetic decision, show that the experiment, which ought to bring tears to the eyes of any person of ordinary sensibility, is thought to instance the discipline of animal research at its most thrilling.

I’m sure that Professor Broadhurst was a kind enough man, though of Harlow one can be rather less certain. Both had wives who helped them in their research, if that’s relevant. As Richard Ryder says in Victims of Science, “My intention is in no way to defame scientists, but to question their conventions.”[vi] And the convention in which Broadhurst was working is very clear: it is the old master/slave convention. And not just at work, where what he calls “the lowly rodent and his laboratory master” live out that relationship. Those two are the template for a much larger project, because, so he proposes, the “exploitation in the service of man of the behavioural resources of animals has hardly begun.” In the editorial foreword to The Science of Animal Behaviour, this “service of man” is frankly and enthusiastically called “slave labour”.

It seemed natural at that time, at least to Broadhurst and his editor, to cast the scientist as the designer of our future relations with animals. So at the same moment that Ruth Harrison, in Animal Machines, was warning of the horrors of industrialized farming, Broadhurst was telling his Pelican audience that the present role of animals in food production would soon “seem pitifully small” (a most interesting choice of adverb). It’s true that to some extent science has begun to provide its own corrective in the new academic discipline of Animal Welfare (where Oxford University has been taking a leading part). But I believe that Broadhurst and his colleagues in the profession would have welcomed this, as keeping the story within the laboratory and its variants, and in the hands of scientists. Besides, science has not been brought to a pause in this matter. New ways of exploiting animals for food, indeed new animals, are being thought up and made real now for new forms of slavery.

No, it’s not by inventing techniques for the study and measurement of animal welfare that speciesism, as exposed in Animals, Men and Morals and still going strong now, can be understood and undone, and new varieties of it prevented. What’s needed of mankind is a “re-appraisal of his position in relation to the creatures with which he shares the environment” That quotation is from Ruth Harrison’s chapter in the book. It’s the chapter about factory farming, but it’s also the first chapter, and it acted as an introduction to what followed. Her first sentence accordingly takes a fully re-proportioning view of our standing in the natural world: “It is a sobering thought that animals could do without man yet man would find it impossible to do without animals.” This is a radical fact: if you read “could” as a past tense (‘were perfectly able to’), you have the whole tragic history of human/animal relations before you. Animals, Men and Morals was the first full statement of that tragedy as it looked in the twentieth century, and the first authoritative call to put it right.

 

[i] Animal Liberation, Pimlico, 1995, p.6

[ii] New York Review of Books, vol.20, no.5, April 5, 1973

[iii] Animals, Men and Morals, ed. Stanley and Roslind Godlovitch and John Harris, Gollancz, 1971, p.232. Later quotations are from p.11.

[iv] Referenced in the text to Journal of Comparative and Physiological Psychology, 1962

[v] The Science of Animal Behaviour, Penguin Books, 1963, p.12. Later quotations are from pp.74, 73, 100, 135, and 132.

[vi] Davis-Poynter, 1975, preface

This post is a revised version of an article first published in the Oxford Magazine (the University’s house journal) in 2013.

Revenge on the Farm

The previous post featured a Teach Yourself title of 1965, Modern Poultry Keeping, championing the new factory model for British chicken-farming nearly new, anyway, for already the toll of chickens eaten in the U.K. had increased from 1 million in 1950 to about 150 million in the year of that book’s publication. Today, it’s approaching 1 billion. And of course biotechnology has been backing or pushing the progress all the way.

Accordingly, most of the 139,000 birds which appear in the Home Office’s statistics for animal research in 2014 were so-called ‘domestic fowl (Gallus domesticus)’. These were chosen to pioneer, test, or otherwise provide information about farm-animal disease (6,512 birds), drugs and poisons (11,045) feed safety (8,553), GM possibilities (798), etc. etc.  Really the word ‘domestic’ is now a sad misnomer for this animal which research and development have done so much to evict from its own or anyone else’s home-life. As the novelist Patricia Highsmith notes, when she sets the scene for her chicken-farm story ‘The Day of Reckoning’, “not a chicken in sight!” This is a fine come-uppance story which I shall, in a moment, add to the category discussed last month under the heading ‘Animal Revenges’ (15 February). But first a little more about science on the farm.

I also mentioned in the previous post Ruth Harrison’s book Animal Machines, which at that same mid-60s time made public the immorality of the new farming. There was a very welcome re-issue of this book in 2013, and in the new introductory pages we are told that although ‘improving animal welfare’ has now become “one of the key ways a scientist can demonstrate the importance and impact of their work”, still “Ruth’s work is not yet done”.

Not indeed, and surely not even as well on the way as those words seem rather complacently to imply. As to ‘improving animal welfare’: that it has become a respectable scientific discipline is certainly a good thing (although 1,509 domestic fowl apparently had to be sacrificed for it in 2014); that it took so long to do so is something which the Royal Veterinary College might reasonably be asked to explain, if it wasn’t for the fact that, being itself a vivisector, that organisation is also itself part of the explanation. For to relegate ‘animal welfare’ (as opposed to mere animal health) for as long as possible to the realm of the ‘sentimental’ amateur has been very helpful to all such institutions. But anyway, even this celebrated advance is partly, perhaps largely, Feather coverage is greatly reduced on the birds, AFPhumbug. Most technical or biomedical innovations in the process of turning animals into food can also, with a little thought and PR, be presented as good for the animals, if that’s also good for their own “importance and impact”. Even the recent grotesque experiment in featherlessness turned out to be altruistic: with their feathers on, it was said, chickens “suffer tremendously” from over-heating in broiler sheds, at any rate in hot countries.

As to Ruth Harrison’s work being “not yet done”, it’s rather the point of that story of Patricia Highsmith’s to show that there’s only one way to get that work done, if we really do want it done, so I shall now turn to ‘The Day of Reckoning’.

The story is set in North America in the early 1970s, but like all good cautionary tales it will do for anywhere, any time a point which I shall illustrate in square brackets here and there. John Hanshaw, a young politics student, is paying a visit to his uncle Ernie’s farm or rather to Hanshaw Chickens, Inc., as it’s proudly called now that Ernie has made the change of farming method urged by our Teach Yourself title. So now there’s a “long grey barn … huge, covering the whole area where the cow barn and pigpens had been”. Ernie Hanshaw himself has turned from husbandman into the sort of engineer that Teach Yourself prefers: “Machine farming”, he exclaims to his nephew; “just imagine, one man – me – can run the whole show!” At meals, his talk is “of vitamins and antibiotics in his chicken feed, and his produce of one and a quarter eggs per day per hen.” [Title of paper to be read at the forthcoming World’s Poultry Science Association meeting at Chester University: ‘The effect of high levels of whole barley with enzyme supplementation on laying hen performance’]

What this change means for the animals, Patrician Highsmith makes plain enough. A modern reader will not be taken by surprise, except perhaps by the so-far modest scale of Hanshaw’s one shed, holding perhaps a few thousand birds. [Application at present before York City Council: plan for a broiler ‘farm’ at Rufforth accommodating 288,000 birds at any one time, with six ‘crops’ a year] The lighting system deludes these young birds into behaving as if it’s Spring, and therefore into wearing themselves out laying eggs steadily for ten months. This and their close confinement (they “couldn’t turn around in their coops”) has so disturbed them that, as Hanshaw’s wife Helen unhappily says, “Our chickens are insane”. But Patricia Highsmith also makes it clear that they have not lost the urge to live according to their nature. They are either trying to do so (“Much of the flurry in the barn was caused by chickens trying to fly upward”), or expressing their frustration at the impossibility, through neurotic behaviour which is in its turn frustrated: “They’re de-beaked. They’d peck each other through the wire, if they weren’t … ever hear of cannibalism among chickens, John?” [Advice from the Virginia Tech Agriculture and Life Sciences faculty: “Don’t take chances! Make cannibalism control part of your management program and you will save a great deal of time and money.”]

By contrast there is, not far away from Hanshaw Chickens Inc., one of those unreconstructed farms of the mixed and under-automated variety so much deplored by Teach Yourself (although, as that book’s author says, “thankfully the numbers become fewer each year”). On this farm, the hens live a more or less natural life: “They can see the sun! They can fly! … And scratch for worms – and eat watermelon!” Those cries of sympathetic pleasure are human, but not therefore necessarily more complex than the pleasures which they respond to. Still, implicit in them there is this much more, an idea of freedom which may turn into something more thought-out and purposeful. So Helen adds, “Sometimes I want to open all the coops in the barn and open the doors and let ours loose, just to see them walking on the grass for a few minutes.” And the same idea is more powerfully represented in a dream which John has that night:

He was flying like Superman in Ernie’s chicken barn, and the lights were all blazing brightly. Many of the imprisoned chickens looked up at him, their eyes flashed silver, and they were struck blind. The noise they made was fantastic. They wanted to escape, but could no longer see, and the whole barn heaved with their efforts to fly upward. John flew about frantically, trying to find the lever to open the coops, the doors, anything, but he couldn’t.

In this brilliantly imagined episode, John Hanshaw, airborne but struggling ineffectually with the man-made machinery, becomes physiologically identified with the chickens and their urge to freedom. At the same time, as a super-man, he is the one active and practical possibility to which they look for its realisation.

And at this point I go back to the comment which Stephen Eisenman added to that post ‘Revenges of the Animals’, mentioning his recent article entitled ‘The Real “Swinish Multitude”’. In that article, he has proposed a way of understanding and acknowledging, as political history, the liberation efforts of animals: a “history from below” of the kind which E. P. Thompson so notably pioneered in his Making of the English Working Class (1963). Without such a history, a resistance or liberation movement lacks the self-awareness and coherent vision which it needs if it is to be cumulative in what it achieves, and if it is to be finally respected and given the place it claims: in short, if it’s to win. As Jason Hribal’s African saying goes, “Until the lion has his historian, the hunter will always be a hero” (see again ‘Revenges of the Animals’). And this is where even the lion must look upward, like Hanshaw’s hens, to higher (or let’s say, different) faculties than he or they possess. But not just in the writing: “All political resistance requires collaboration, mutual aid, and action in common”, says Stephen Eisenman: “… This is how animal protest occurs – sympathy and collaboration between humans and animals striving for liberty.”

Even purely human revolt is driven by a full spectrum of motive, from the most deeply buried collective instinct to flourish (“the whole barn heaved with their efforts”), through to the intellectually formulated insistence on the right to do so. Anyone who has ever been part of an impassioned demonstration will have felt this. All of the less verbalised region of motive we can share with the animals: but it is up to us, as specialised thinkers, to supply what Eisenman calls “higher level executive function”, our capacity to deal with the man-made world and its machinery, political and material. It’s what John Hanshaw tries to supply in his dream, sharing but also rising out of the common urgency of the barn to do so.

Stephen Eisenman summarises thus: “animals live in a political and not simply a biological arena; … they communicate to each other and to us their desires for safety, companionship, and love; and … their aspirations for freedom cannot be easily separated from the project of human emancipation.” It’s the meaning of Patricia Highsmith’s story too. The hens are a pathetic few months old, hardly more than children, but they have an insistent collective interest, clearly communicated, and as clearly refused by force. It’s a political situation. And bound into it is a human bafflement only slightly less poignant. For the farm is an inhuman place for the people as well as for the animals: seed sack bleak and dangerous. [See label, right, from a sack of dressed seed.] The sort of thing that happens to the Hanshaws’ kitten, run over by one of the huge service-vehicles (its flattened corpse is the first and emblematic sign of ‘life’ that John sees when he first arrives on his visit), might equally happen to one of the family and indeed does. The young daughter is caught and killed under a descending grain-container. And it’s this shock that precipitates the “reckoning” of the title. What John only attempted in a dream, Helen, the bereaved mother, gets done. The hens, themselves bereaved mothers though they haven’t ‘known’ it, come pouring out of the sabotaged barn and, though scarcely able to walk (“staggering, falling on their sides … falling backwards”), begin to reclaim their species-life, their birthright: “Look! … They don’t know what grass is! But they like it!” And John and Helen share in this liberation: they and the chickens are equally described as “mad”, a revolutionary madness perhaps.

As for poor Ernie, obsessed and (not unlike his hens) wretchedly depreciated by the mechanisation he thinks so highly of … well, the “reckoning” itself is between him and the hens, and readers of Patricia Highsmith will guess that it’s surprisingly unpleasant.

‘The Day of Reckoning’ was published in 1975, part of a collection of stories called The Animal-Lover’s Book of Beastly Murder. All but one are come-uppance stories, mostly told from within the mind of the animals (“history from below”, in fact): elephant, camel, truffle-pig, rat, goat, and others. The exception is a fine study, likewise from within, of a fastidious cockroach, though even he (it is a he), by making his way in a hostile man-made world, triumphs. That punning title, Beastly Murder, may initially seem to mean ‘horrible murders by animals’. But as you read the stories, the libellously pejorative sense of ‘beastly’ is worn away, and the title comes rather to mean the murders which animals might be driven to commit  in pursuit of, and within the means of, their proper nature: beast-like bids to live beast-like lives.

“Agriculture”, says the University of Wisconsin-Madison, “is applied biology, and it’s where a lot of today’s cutting edge science is getting done.” No; freedom is applied biology, and it’s in accordance with that principle that we must re-write animal history, in words and in their lives and our own.

 

[References: the 2013 edition of Animal Machines is published by CABI, and Beastly Murder (1975) by Heinemann; Stephen Eisenman’s article appears in Critical Inquiry, vol.42, no.2 (Winter 2016), pp.339-373; the quotations from research institutions and the Home Office animal research analysis can be found on the relevant web-sites; featherless chicken report from BBC Online News, 21 May 2002.]

Pharming Today

A chart showing the numbers of animals used in experiments in U.K. universities during 2014 (the most recent reportable year) puts Oxford University top, with its grand score of 226,739 – ahead of its nearest rival Edinburgh by about 25,000.

It may be that Oxford University’s scientific leadership takes quiet satisfaction in this result, if they’ve noticed it, as tending happily to confirm the University’s pre-eminence in biomedical science. After all, wasn’t this what their new building was for, to secure Oxford’s traditional place as the nation’s prime Laboratory, South Parks Roadcentre of animal research? However, as posted on the Oxford Students for Animals facebook page (and many others), the new information is headed ‘How many animals has your university killed?’, so it’s evidently not intended to please the contestant institutions, or the students whom they train in the practice. Accordingly there’s a defensive (but temperate) comment underneath it, from a medical scientist at Nottingham. He compares the lives of the U.K.’s laboratory animals favourably with those of animals on factory farms, and ends with this advice: shut the meat industry down FIRST before you try and curb the use of animals for discovering the drugs that cure our diseases.”

In one form or another, it’s a very familiar defence or put-off – as old, perhaps, as the vivisection debate itself (though not for that reason either right or wrong). It was certainly in use when the question first came before the British Parliament by means of a Royal Commission in 1875-6. Among those who tried it was the man who later became Oxford University’s first professor of Physiology, John Scott Burdon Sanderson. Part of his evidence tending to show that laboratory animals didn’t need legal protection was that ‘game’ animals were much worse off: the man had been a keen hare-courser, so of course he would have known what he was talking about. In 1927 the same argument was used by H. G. Wells in an article for the Sunday Express, in whose pages George Bernard Shaw soon afterwards demolished its moral logic thus: “This defence fits every possible crime from pitch-and-toss to manslaughter. Its disadvantage is that it is not plausible enough to impose on the simplest village constable.” Pitch-and-toss, incidentally, was a game of mixed skill and chance, played with coins, and was at one time illegal as a form of gambling, if played in the street: not as bad as picking pockets, no doubt, which in turn was not as bad as … etc., etc., until the argument comes to rest just short of mass murder.

Still, the defence is being made in this present instance by a researcher at Nottingham University, an institution which, though itself a user of animals in research (scoring a modest 17,924), does also accommodate the laboratories of the excellent Fund for the Replacement of Animals in Medical Experiments (FRAME). It therefore surely deserves a more considered reply than the Shaw quotation, and I shall try to give at least part of one.

Why, then, don’t anti-vivisectionists turn their attentions to the far greater suffering (numerically, certainly, and perhaps also in most other respects) endured by factory-farmed animals?

The first thing to say is that of course they do. I’ve used the word ‘turn’ to highlight the sleight of hand in the argument; most, if not all, anti-vivisectionists can and do have both wrongs clearly in view concurrently, as well as a whole range of others. It’s all one subject, though individuals and organisations may specialize within it: hence the one collective term by which Peter Singer identified it in the first sentence of Animal Liberation in 1975, “the tyranny of human over non-human animals”.

But vivisection is, besides, bound in with factory farming in a more particular and unpleasant way. The move from husbandry to mass-processing of farm-animals has been made possible at every stage by scientific research, including biomedical research. (Burdon Sanderson himself devoted his early vivisectional research to disease in cattle.) When Ruth Harrison first showed the public what was happening on Britain’s farms, in her book Animal Machines (1964), she made this fact very clear: “every batch of animals reaching market is a sequel to another experiment or part of an experiment.” The livestock farm and its farmer were being made dependants of the laboratory and the scientist. How far this has gone since then can be read in any issue of Farmers Weekly.

For even while Ruth Harrison was publicizing the wretched effects of this development, other voices were busily promoting it. One such was a 1965 volume in the ‘Teach Yourself’ series (of all innocent publishing brands), entitled Modern Poultry Keeping. The word ‘keeping’ has an old-fashioned suggestion of husbandry about it, but any readers of this book foolish enough to be expecting to teach themselves a job in agreeably rural surroundings, perhaps amateurishly collecting eggs in a basket, like the wholesome woman on the old Ovaltine tins, were indignantly corrected. It was now a “highly specialized business calling for men [N.B.] with a wide technical knowledge”. Raising table-poultry, for instance, “consists wholly in rearing birds that will carry the maximum amount of flesh in the shortest possible time, at the lowest cost.” You need maths, biology, and a good grounding in what the book calls “light engineering” to get that right – or someone else does, to get it right for you. And of course that “technical knowledge” also includes knowledge of the pharmacopoeia: oestrogen pellets to ‘caponize’ the would-be cockerels, antibiotics against disease, and so on.

Then there’s animal behaviour. The Nottingham scientist specifies this in his comment, reasonably enough, as one of the things that cannot be studied without the use of real animals, and indeed it’s been responsible for some of the most cruel and shameful scenes in laboratory history. Another book contemporary with Animal Machines, P. L. Broadhurst’s Science of Animal Behaviour (1963), reviewed some of these scenes, but not apologetically; on the contrary, the author took the view that the “exploitation in the service of man of the behavioural resources of animals has  cowhardly begun.” In particular he looked forward to a time when the “pitifully small” role so far played by animals in food-production would be greatly expanded, using the knowledge gained in the laboratory of what they can be induced or compelled to do: not just to make food out of themselves at minimum expense, that is, but also to pick fruit or mind machinery, or more generally to be what his book, with naïve but untouching enthusiasm, calls “slave labour”.

So much for agriculture as envisioned from the laboratory. That things on the farm are only as bad as they are, and not as they might have been (and may yet be), can at least partly be attributed to the ‘curbing’ of such dreams at source. It’s very much harder to correct them once they’ve become real.

*     *     *

The man usually regarded as the founder of experimental physiology, the Frenchman Claude Bernard – a bust of whom stood on our own Burdon Sanderson’s mantelpiece in Oxford – proudly described and championed his science’s characterizing spirit as “éminemment conquérant et dominateur”. That spirit of tyranny was glaringly evident in Bernard’s own work, so much so that one of his assistants subsequently wrote, “I cry off, and am prepared to see not only science, but even mankind, perish rather than have recourse to such means of saving it.” Unfortunately Bernard’s version of the scientific spirit has survived through more than 150 years of vivisection right up to the hideous attempts of recent years at xeno-transplantation and even (not in the U.K.) the transplanting of animal heads. It’s not only farming which is pervertable by science such as this. No doubt biomedical research has produced valuable knowledge and great benefits. But some of that research, both the valuable and even more tragically the worthless, has been at a cost to animal lives, and to human decency, which no real or speculative benefit to ourselves should have been allowed to justify. So far from leaving such research to itself for a while, it’s our duty to all animals, including ourselves, to do continuously everything we can to curb it.

 

[Quotations: G. B. Shaw from Shaw on Vivisection, ed. Bowker, 1949, p.35; Animal Machines, 2013 (2nd edition), pp.37-8; J. I. Portsmouth, Modern Poultry Keeping, pp.2 & 5; Science of Animal Behaviour, p.132 & foreword; Claude Bernard and George Hoggan quoted in John Vyvyan, In Pity and in Anger, 1988, pp.46 & 77]