aon REPORTS ON THE STATE OF SCIENCE.—1913. 
forces, such as the simple geometrical markings which are structure revealed, 
through more irregular stripes and blotches, which may be set down to ir- 
regular growth, first to a uniform colouration which obliterates the structural 
form, and lastly to odd and brilliant disguises of the true contours of the body. 
I do not doubt but that natural selection has attended each stage of the process, 
now rejecting and now favouring the patterns that have emerged from the 
laboratory of nature, as they turned out to be harmful or useful. 
Comparison of the lower and higher groups of mammals and of the earlier 
and later stages of individuals would appear to lead to the inference that 
primitive mammals were spotted or striped. Spots and stripes become in- 
creasingly frequent as we pass from the higher to the lower groups. If the 
adults are spotted, the young are, I believe, always spotted; if the adults are 
striped, the young are always either spotted or striped; when the adults are 
self-coloured, or when they display the strange markings which conform with 
none of the structural lines of the body, and which Abbot Thayer has inter- 
preted as ‘ruptive’ or outline-breaking, the young are striped, spotted, or 
uniform, 
Man and his allies, the apes, monkeys, and lemurs, compose what we must 
regard as the highest group of mammals, and among them stripes and spots 
are extremely rare in the adult or in the young, the most obvious cases being the 
rings on the tails of lemurs. The tiger, leopard, jaguar, and cheetah are 
familiar instances of striped and spotted carnivores, and their young are always 
striped or spotted. But the young of the self-coloured lion, puma, and caracal 
are spotted, and lynxes, which are greyish-brown in the adult summer coat, are 
brilliantly spotted with black when young. Small carnivores such as civets 
and genets, binturong and ichneumons, have many striped and spotted forms, 
and here, again, the young of the striped and spotted creatures are always 
striped or spotted, and the young of the self-coloured animals are not in- 
frequently striped or spotted. Antelopes are not often striped or spotted, but 
the banded duiker, which is marked with hoops across the back, has young 
with a similar pattern. The South African eland shows almost no traces of 
striping when it is adult, but the calves have barrel-like hoops of white, and 
in the Derbian eland and the kudus, where the stripes persist through life, the 
young have them more strongly marked. Sitatunga antelopes are nearly 
devoid of stripes in the adult condition, but their young are brightly striped 
and spotted. The bongo and angas antelopes and the beautiful harnessed 
aptelopes are striped, although the stripes tend to disappear in old bulls, and 
their young are vividly striped. The young of a large majority of different 
kinds of deer are spotted; sometimes the spots are retained throughout life; 
scmetimes they are found only in the brighter coats of summer, sometimes the 
disappear altogether. But I do not know of any spotted deer with self-coloured 
young. ‘The young of true wild swine, pygmy hogs, river-hogs, and wart-hogs 
are marked with longitudinal stripes that disappear in the adult. The young 
cf the American and Malay tapirs are striped and spotted. Spots, dapplings, 
end stripes are more common in foals than in adult horses and asses. The 
foals of all the zebras are vividly striped, and there seems reason to believe that 
the less striped forms are the descendants of forms that were more fully 
marked. Among the rodents many are marked with stripes or with spots 
arranged in longitudinal rows, and the young of the striped forms are always 
striped. A good many marsupials are spotted or striped, and precisely the 
same condition obtains; the young of the striped or spotted animals are always 
striped or spotted. 
The suggestion was made many years ago, I think first by Dr. Bonavia, 
that these spots and dapplings, so frequent and so plainly ancestral, were 
legacies of a primitive coating of scales like the armour of armadillos and of 
their gigantic extinct allies, and it is at least a fair speculation that they are 
to be associated with the scaly covering of the reptilian ancestors of mammals. 
Without pushing the argument to this extreme, we may at least assume that the 
presence of spots, reticulations, and stripes (the latter being expanded spots or 
fused rows of spots) are indications or revelations of the composite nature of 
the skin, which is not merely a uniform sheet stretched over the surface of the 
Lody, but a structure growing from many centres. Like the cranial and spinal 
nerves, these centres were no doubt fundamentally segmental in character, but 
—— 
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