2l6 



DESIGN IN NATURE 



RECENT 



A A. EqvTUS. 



PLIOCENE 



B 



.B. Plioliippus. 



MIOCENE 



C C. Protohippus {Hiiyparion). 



It is no easy matter to deal satisfactorily with the organs of locomotion as apart from a First Cause, Law, 

 Order, and Design. Given these, there is no difficulty. The subject resolves itself into cause and effect, and tne 

 ends attained are always explained by the means employed. 



The modifications in the fore arm, &c., of the ox, horse, and swan are given at Plate Ixxvi. 



This plate gives comparative views, and shows the modifications, more especially m the tore arm, wrih,^, 

 hand^L'phalanges, of L ox, horse, and wing of the bird. In the ox, the fore arm 1^- *- /f J.f^j 

 with two hoofs. In the horse the fore arm has only one digit and one powerful hoof. In the wing of the bird 

 ^ bones of the hand and fingers are mixed up and soldered together to give additional strength for supporting 

 tne Dones oi we n<tnu g r ^^^ ^^^^^ ^^ ^^^ primary and secondary 



feathers in flight. The modifications 

 referred to are very striking, and are 

 connected with the locomotion of the 

 several animals. They have nothing to 

 do with heredity and descent, not even 

 in the horse, which is generally regarded 

 as a direct descendant of a five-toed 

 mammal. In the ostrich the foot con- 

 sists of two digits— the one being very 

 much larger, stronger, and longer than 

 the other. Here again the exigencies 

 of locomotion afford the true explana- 

 tion of the arrangement. In this quaint 

 bird, which walks and runs on loose 

 sand, the large digit performs the of&ce 

 of a foot. The extinct moa had three 

 digits and a rudimentary fourth one, 

 and the modern emu has three digits to 

 each foot. In these running birds the 

 dropping of digits is very suggestive and 

 remarkable. The horse and ostrich are 

 the fleetest of existing land animals. 



The supposed descent of the horse, 

 according to Huxley and Marsh (especi- 

 ally the latter), from a five -toed mammal 

 is illustrated at Fig. 41. 



In Fig. 41 the foot of the horse is 

 traced from past to present time — from 

 the Eocene, Miocene, and Pliocene 

 until we reach the '\ Pleistocene, or 

 recent period. The oldest horses were 

 said to be about the size of a large dog. 

 The following is the supposed order of 

 succession : Orohippus (Eocene), with 

 four toes to the fore leg and three toes 

 to the hind leg ; Mesohippus, with three toes and an imperfect fourth toe to the fore leg, and three toes to the 

 hind leg ; Miohippus anchitherium (Miocene), with three toes each to fore and hind limbs ; Protohippus liip- 

 parion, with three toes each to fore and hind limbs, the outer toes becoming thinner and shorter and not quite 

 reaching the ground ; Pliohippus (Pliocene), with three toes to each fore and hind limb, the outer toes becoming 

 so thin as to be mere rudiments, and being far removed from the ground ; Equus (Recent), with three toes to each 

 limb, but the outer toes so shrunken as to be scarcely recognisable even as vestiges. In these transformations the 

 central toe of each foot is from the first the largest : it gradually hypertrophies : the outer toes becoming meanwhile 

 smaller and smaller. 



In the lapse of time, in the opinion of Huxley and Marsh and evolutionists generally, a new animal is formed. 

 There is no warrant for such a conclusion. The dwarfing and virtual suppression of portions of limbs is not 

 confined to the horse. It occurs in several animals, as the Pterodactyl, or flying reptile, and the diving and flying 



EOCENE 



D D. Mioliippus (Anchitherium). 



.E. Mesohippus. 



F F. Oroliippus. 



Fig. 41. — In tliis iigure the feet and bone limbs of the horse (Equus cahallus) are com- 

 pared with those of its supposed ancestors, a, Fore foot ; h, hind foot ; c, fore arm ; d, leg 

 (after Huxley). 



