432 PRIMARY FACTORS OF ORGANIC EVOLUTION. 



in a fight. Soon after, and while the wound was very 

 malignant (it never entirely healed), he was turned 

 into a flock of game hens of another strain. He was 

 otherwise healthy and vigorous. A very large propor- 

 tion of his progeny had the corresponding eye defec- 

 tive. The chicks were not blind when hatched, but 

 became so before attaining their full growth ; some at 

 the time of acquiring the pin-feathers, others later and 

 before reaching maturity. The hens afterwards pro- 

 duced normal chickens with another cock. Both 

 strains had been purely bred for ten or more years, 

 and none of the fowls had been blind unless from 

 fights. 



' '(This case was reported to me by an educated 

 and reliable breeder of game-fowls.) 



" c. A hunting mare had a split pastern and was 

 then used for breeding. Her first, third, and fourth 

 foals were sound, the second one had 'almost an exact 

 reproduction of the mare's unsoundness.' 



"(This is on the authority of the celebrated veteri- 

 nary surgeon, Clement Stevenson, as occurring under 

 his own observation, ' not hearsay. ' Live Stock Jour- 

 nal, London, November 23, 1888, p. 508.) 



"d. A female (and very prolific) cat, when about 

 half grown met with an accident. ' Her fine, long tail 

 was trodden on and had a compound fracture, two ver- 

 tebrae being so displaced that they ever after formed a 

 short offset between the near and far end of the tail, 

 leaving the two out of line. At first I noted that out 

 of every litter of kittens some had a tail with a querl 

 in it.' With successive litters the deformity increased, 

 until 'not a kitten of the old cat had a straight tail, 

 and it grew worse in her progeny until now we have 

 not a cat with a normal tail on the premises,' (in a cat- 



