CHAPTER VI 



COLOURS AND PATTERNS OF YOUNG MAMMALS 



The difference in coloration between young mammals and their 

 parents often depends simply on immaturity. The skin may be 

 smooth and soft, the scanty hair sUky in texture, and the general 

 coloration pale, merely because the young animals are not yet 

 fuUy developed, because their structure is incomplete and the 

 physiological processes which produce pigment are feeble and in- 

 effective. The little creatures, in fact, may remain partly embryonic 

 after they are bom, and differences due to this belated development 

 are especially plain in those species where the young are feeble and 

 most dependent on their parents. The first liveries acquired by 

 such animals, as well as the liveries of those that come into the 

 world active and furry, often differ in a remarkable way from the full 

 dress of the adults. If the adults are spotted, the young are always 

 spotted ; if the adults are striped, the young are either striped or 

 spotted ; even if the adults are self-coloured, or have acquired one 

 of the striking patterns of the higher grades that not only do not 

 conform with the architectural lines of the body but serve to 

 disguise or interrupt these, then the young may still be striped or 

 spotted. 



I do not think that there is any doubt as to spots and stripes being 

 simple growth patterns, outcrops of actual structure, and not 

 devices that have been invented, so to speak, by nature for special 

 purposes, although as they were present they have often been turned 

 to account. A good many years ago. Dr. Bonavia, an ingenious 

 surgeon-naturalist, published a number of essays on the markings 

 of mammals, and compared such patterns as the dappling of horses, 

 the rosettes of the jaguar, the spots of leopards and of other cats, 

 with the armour-like scales of armadillos and their gigantic extinct 

 aUies. Certainly many of the extinct mammals were armoured, 

 and if we go back still further to the reptUian ancestors of mammals, 

 we come to a set of creatures in which a coating of heavy, sculptured 

 scales was the rule and not the exception. It would be pressing the 



8i F 



