n6 STUDIES IN THE EVOLUTION OF ANIMALS 



cases it may endure better, and the variations may become extinct ; 

 while in other cases, the variations may endure better, and the 

 parent form may become extinct 



Thus we see Monkeys themselves varied in a hundred ways, 

 enduring side by side with man, who possibly originated from the 

 Monkey-plane, and they may continue to endure until perhaps they 

 become his rivals, and competitors for the consumption of his crops. 



Professor Parker l says : ' Why such a form as the Glyptodon 

 should have failed to keep his ground is a great mystery ; nature 

 seems to have built him, as Rome was built, for eternity. His 

 exquisite little relative, the Chlamydophorus, scarcely larger than a 

 Mole, has continued as yet to run out of danger, safe in his little- 

 ness ; and many other kinds of low-brained mammals have, so to 

 speak, the power to make themselves practically invisible.' 



In another place I have ventured on a speculation which may 

 account for the descendants of the Glyptodonts losing their carapace. 



All these armour-plates of existing and extinct animals are 

 most suggestive, and I consider them very important elements in 

 the interpretation of the rosetting of the Jaguar. 



After the armoured animals lost their skin-stiffening of lime 

 deposit, the imprints of armour-plating must have become vastly more 

 subject to modification than before, and so we have the endless 

 forms of spotting and marking in mammals. After millions of 

 generations that have been born since the Glyptodonts, and other 

 Armadilloid animals, lost their bone-plates, it cannot be expected 

 that the skin should retain the original outlines of plates un- 

 changed. The great wonder is that the Jaguar has retained the 

 features of its ancestral bone-plates with so little modification \ 



As an instance of the slowness, under favourable circumstances, 

 with which long established characters are got rid of, both from the 



1 Mammalian Descent, p. 94. 



