SPOTS AND STRIPES IN MAMMALS 35 
again, may be regarded as a transversely striped marsupial, 
although here the stripes are few in number and approxi- 
mate in form to blotches. Although in the same order the 
dasyures are spotted with white, we have no black-spotted 
marsupial; and if such a type formed the transition 
between longitudinal and transverse stripes, surely some 
species showing such a type of coloration ought to have 
persisted. 
Then, again, in the ungulates we have the zebra- 
antelopes, the gnus, and the zebras showing most strongly 
marked transverse dark stripes; but we have no dark- 
spotted forms in the whole order except the giraffes, while 
the only ones with dark longitudinal stripes are young 
pigs. And it would thus appear that, although all the 
animals above mentioned are highly specialised species, 
these tranverse stripes and dark blotches must have 
originated de movo quite independently in each of the 
groups in question. Indeed, when we remember that the 
coloration of zebras, antelopes, and giraffes is generally 
of a protective nature—the stripes of the former rendering 
the animals invisible on sandy ground in moonlight, and, 
to a great extent, also in sunlight, while the blotches of 
the latter harmonise exactly with the chequered shade 
thrown by the mimosa-trees among which they feed—it 
is incredible that both types should have been evolved, 
according to a rigid rule, from animals marked by dark 
longitudinal stripes. 
Another instance of the same nature is afforded by the 
cats, in most of which the coloration appears to be 
mainly of a protective nature, plain-coloured species, like 
the puma and lion, having tawny coats harmonising with 
the sandy deserts which these animals often inhabit, while 
the vertical stripes of the tiger, although in some degree 
