182 STUDIES, SCIENTIFIC AND SOCIAL chai-. 



or drowned by the giving way of ice. Caverns were the 

 haunts of hyaenas, tigers, bears, and other beasts of prey, 

 which dragged into them the bodies of their victims, and 

 left many of their bones to become imbedded in stalag- 

 mite or in the muddy deposit left by floods, while 

 herbivorous animals were often carried into them by these 

 floods, or by falling down the swallow-holes which often 

 open into caverns from above. But, owing to their arboreal 

 habits, monkeys were to a great extent freed from all 

 these dangers. Whether devoured by beasts or birds of 

 prey, or dying a natural death, their bones would usually 

 be left on dry land, where they would slowly decay under 

 atmospheric influences. Only under very exceptional cir- 

 cumstances would they become imbedded in aqueous 

 deposits ; and instead of being surprised at their rarity 

 we should rather wonder that so many have been dis- 

 covered in a fossil state. 



Monkeys, as a whole, form a very isolated group, having 

 no near relations to any other mammalia. This is un- 

 doubtedly an indication of great antiquity. The peculiar 

 type which has since reached so high a development must 

 have branched off the great mammalian stock at a very 

 remote epoch, certainly as far back as the Secondary 

 period, since in the Eocene we find lemurs and lemurine 

 monkeys already specialised. At this remoter period they 

 were probably not separable from the insectivora, or 

 (perhaps) from the ancestral marsupials. Even now we 

 have one living form, the curious Galeopithecus or flying 

 lemur, which has only recently been separated from the 

 lemurs with which it was formerly united, to be classed as 

 one of the insectivora ; and it is only among the O^jossums 

 and some other marsupials that we again find hand-like 

 feet with opposable thumbs, which are such a curious and 

 constant feature of the monkey tribe. 



This relationship to the lowest of the mammalian tribes 

 seems inconsistent with the place usually accorded to 

 these animals at the head of the entire mammalian series, 

 and opens up the question whether this is a real supe- 

 riority or whether it depends merely on the obvious 

 relationship to ourselves. If we could suppose a being 



