GENERAL CONCLUSIONS 329 



moved about, enabled them to track their associates ; certain other 

 ruminants have lost these skin glands, and, instead, have vestiges 

 of them, shown by tufts of hair contrasted in colour and length 

 with the surrounding surface ; 



(2) There is suspicion that the one big digit of the hand and 

 foot of the Horse was in origin double, like that of the ruminants. 

 In the latter, the two metacarpal and metatarsal bones fused into 

 a ' cannon ' bone, the phalangeal bones remaining separate ; while 

 in the Horse the metacarpal and metatarsal, and the phalangeal 

 double bones, fused into single bones throughout the series. There 

 is some evidence to show that the Horse is more closely related to 

 the ruminants than he is to the Rhinoceros ; l 



(/) As monstrosities occur now, they may, with greater reason, 

 have occurred in past ages. If this be admitted, it will be seen 

 that a much shorter time can be allowed for bringing about great 

 modifications in the species of the present and the past times than 

 would be needed by slow and gradual accumulation of minute 

 variations, which is the theory accepted by most biologists. 2 



1 Since writing these conclusions, I came across Mr. Bateson's Materials for the Study 

 of Variations. In Fig. 120 he gives a 'solid-hoofed' Pig, with the iii. and iv. digits 

 fused into one large digit throughout, like that of the Horse. 



2 Mesoplodon Layardi is a beaked whale, with only two strap-like teeth. Professor 

 Moseley, of the Challenger, observes that ' these two teeth in the adult animal become 

 lengthened by continuous growth of the fangs into long curved tusks. These arch over 

 the upper jaw or beak, and, crossing one another above it at their tips, form a ring round 

 it and lock the lower jaw, so that the animal can only open its mouth for a very short 

 distance. . . . How the animal manages to feed itself under these circumstances is a 

 mystery. . . . That these enormous teeth can be of no possible advantage to their owner 

 appears perfectly clear ; and they must probably be regarded as affording an instance of 

 semi-monstrous development analogous to the one displayed by the tusks of the Babirusa.' 

 Roy. Nat. Hist., vol. iii. p. 35. 



