The book's general method is to present a wide range of examples from across the animal kingdom of each type of coloration, including marine invertebrates and fishes as well as terrestrial insects, amphibians, reptiles, birds and mammals.

Part 1, concealment, covers the methods of camouflage, which are colour resemblance, countershading, disruptive coloration, and shadow elimination.

Examples are chosen from mammals, insects, reptiles and marine animals, and empirical evidence from feeding experiments with toads is presented.

Since the war it has formed the basis for experimental investigation of camouflage, while its breadth of coverage and accuracy have ensured that it remains frequently cited in scientific papers.

It is full of detailed observations of types of camouflage and other uses of colour in animals, and illustrated by the author with clear drawings and photographs.

[P 1] Cott's method is to provide a large number of examples, illustrated with his own drawings or photographs, showing animals from different groups including fish, reptiles, birds and insects, especially butterflies.

For example, the fish Chaetodon capistratus is described as follows:[P 2] this species had the habit of swimming very slowly tail first: but when disturbed it darts rapidly off to safety in the opposite direction... C. capistratus adopts the same tactics... [This fish] is of particular interest in that the real eye is obliterated and a false eye substituted in one and the same animal.Cott was well aware that he was publishing in wartime.

For example, in the section on 'Adaptive Silence', the kestrel is said to "practise dive-bombing attacks", or "after the fashion of a fighter 'plane" to fly down other birds, while "Owls have solved the problem of the silent air-raid"; Cott spends the rest of that paragraph on the "method which has recently been rediscovered and put into practice" of shutting off a bomber's engines and "gliding noiselessly down towards their victims" at Barcelona in the Spanish Civil War.

[P 3] In the concluding chapter, Cott explicitly states "The innumerable visible devices used ... in peacetime and in wartime ... are merely rediscovered ... applications of colour that have already reached a high ... degree of specialization and perfection.. in the animal world", mentioning predator-prey relationships, sexual selection and signalling to rivals.

He then compares the "hunting disguises put on ... as a means of approaching, ambushing or alluring game, and the sniping suits, concealed machine-gun posts, and booby traps" with the camouflage of animal predators; and similarly he compares "protective disguises" with the "photographer's hide and the gunner's observation post."

The Automobile Association has adopted a system of coloration [black and yellow] whose copyright belongs by priority to wasps and salamanders.

7 illustrate the value and effectiveness of maximum disruptive contrasts better than any verbal description... On looking at these drawings from a little distance, it will be seen that the conspicuous patches operate most efficiently in distracting attention from the form of the animals wearing them.

His readers are invited to look first at the right-hand images to gain an idea of the power of "these optical devices" as camouflage, putting off the moment when the animal is actually recognised.

This wonderful bird ... habitually selects the top of an upright stump as a receptacle for its egg, which usually occupies a small hollow just, and only just, large enough to contain it.... the stump selected had thrown up a new leader just below the point of fracture;... the bird sat facing this in such a way that when viewed from behind they came into line and blended with the grey stem.

The book ends by comparing human artefacts and "natural adaptations", both of which can have goals (recall the publication date of 1940, early in the Second World War) including "the frustration of a predatory animal or of an aggressive Power".

Julian S. Huxley wrote a foreword (labelled 'Introduction') which defends the Darwinian concept of adaptation, especially of colour (in animals) and within that frame of mimicry.

", and more sharply that "aggressive and alluring resemblance" (Huxley's words) "must probably be set down as products of fancy belonging to uncritical times.

"[2] Huxley's reply is simply[P 12] Dr. Cott, in this important book, has turned the tables with a vengeance on objectors of this type... Had they taken the trouble to acquaint themselves with even a fraction of the relevant facts to be found in nature, they could never have ventured to enunciate such sweeping criticisms: their objections are a measure of their ignorance.With objections dismissed, Huxley remarks that "Dr. Cott is a true follower of Darwin in driving his conclusions home by sheer weight of example," observing that "Faced with his long lists of demonstrative cases, the reader is tempted to wonder why adaptive theories of coloration have been singled out for attack by anti-selectionists."

[P 12] Huxley concluded his introduction by describing Adaptive Coloration as "in many respects the last word on the subject", upholding the great tradition of "scientific natural history".

The English zoologist Edward Bagnall Poulton, a Darwinian, had written a 360-page book, The Colours of Animals, fifty years earlier in 1890,[3] and he was able, at age 84, to review Cott's work in Nature on its appearance in 1940, beginning with the words This excellent work, eagerly awaited for many years, will be most welcome to naturalists, even, we may hope, to the few who have hitherto rejected the Darwinian interpretation which the author has here supported by a mass of additional evidence based on his own observations and those of very many others.The ichthyologist Carl Leavitt Hubbs, reviewing the book for American Naturalist in 1942, began In this Neodarwinian epic Dr. Cott stamps himself as a true disciple of the master evolutionist.

An immense body of facts and interpretation, much of it original, has been judiciously considered and brought to bear on the question of the biological significance of coloration.Hubbs notes that Cott is seeming concerned about the scarcity of experimental data for the survival value of camouflage, and accordingly relies on Sumner and Isely's "clear-cut results", but at once continues that Cott relies on "the general lore of natural history".

The review ends by mentioning that while biologists (of the 1930s) usually "reject the influence of Natural Selection in evolution, the facts of adaptive coloration as given in Mr. Cott's work are a strong argument in its favour, and must be given due weight.

"[6] Peter Forbes, in his book Dazzled and Deceived, wrote that[7] Cott's Adaptive Coloration in Animals must be the only compendious zoology tract ever to be packed in a soldier's kitbag.

Although Cott does report experiments on predation to test the efficacy of mimicry and camouflage, the book is essentially a narrative of examples plus theory.

Sören Nylin and colleagues observe in a 2001 paper that Adaptive coloration in animals has been a very active research field in evolutionary biology over the years (e.g. Poulton 1890, Cott 1940, Kettlewell 1973, Sillen-Tullberg 1988, Malcolm 1990), and one in which the Lepidoptera have always featured prominently as model species.As a natural history narrative on what has become an intensely researched experimental subject,[9] Adaptive Coloration could be thought obsolete, but instead, Peter Forbes observes "But Cott's book is still valuable today for its enormous range, for its passionate exposition of the theories of mimicry and camouflage".

Cott ruffled fewer feathers [than Trofim Lysenko or Vladimir Nabokov], and his well-organized and unfanatic ideas proved militarily effective, even under the scrutiny of improved techniques for target detection.

Thayer’s principles reemerged in more temperate and rational terms, and camouflage schemes based on them survived both photometric analyses and enemy encounters.