THE ONE BIG DIGIT OF THE HORSE 



247 



Elephant could not pair with a diminutive one, and thus the two 

 breeds would remain distinct. 



Mr. J. I. Lupton^ is of opinion that 'The land upon which 

 every species of animal is bred exerts a powerful 

 influence upon it for good or evil. We find 

 that a sterile soil will stunt the growth of animal 

 life, whereas a rich one will promote vigour, 

 size, and stoutness.' 



Although abundance of food, or the reverse, 

 may have a great deal to do with giant and 

 dwarf forms, still the abnormal size may have 

 been initiated as a montrosity suddenly?- 



Then the Pachynolophus form of foot would 

 seem derivable from a Phcenacodus form of 

 foot. The latter has five digits, with the third 

 enlarged, while the former has only four, with 

 the corresponding, or homologous one, also 

 enlarged, while its big toe is suppressed. 



It should be noted that, as an anomaly, the 

 hand of the Pig sometimes comes out with five 

 digits as shown in Fig. 89. The curious part of this anomalous 

 Pig's hand is that one of the carpal bones, — the trapezium [b) — is 

 completely fused with the metacarpal bone of the thumb, 



From this anomalous hand it would appear that the sub-division 

 of the ungulates or hoofed mammals into uneven-toed and even- 

 toed is rather arbitrary, for here is an even-toed Pig giving birth to 

 an uneven-toed child. Of course both sub-divisions originated from 

 the same stock ; but two Greek names to indicate a condition 



Fig. 89.— Abnormal 

 hand of a Pig, [a] being 

 the thumb, and {b) the 

 trapezium, one of the 

 wrist bones fused with 

 the palm bone of the 

 thumb; from Fleming's 

 translation of Chau- 

 veau's Anat. Comp. des 

 Animavx domestiques, 

 p. 122. 



^ 'Pedigrees of British and American Horses' (Nineteenth Century, June 1894, 

 p. 926). 



2 See 'Nanisme et Geantisme,' Guinard, Precis de Tiratologte. 



