1 8 CASTRATION OF CRYPTORCHID HORSES. 



ternal form, especially about the neck and head, becomes some- 

 what like that of the stallion, although this rule is not constant. 



A condition is occasionally met with in which no testes are 

 present at all.^ Such an animal is technically known as an 

 " anorchid." 



Many apparent hermaphrodites have predominating male 

 tendencies, and prove upon exploration to be cryptorchids. In 

 some parts of England a horse with this malformation is known 

 under the name of a " will-gill " by the farmers. 



Heredity. — There can be no question upon this point. The 

 tendency for a horse with one testicle retained and one in the 

 scrotum to produce progeny having a similar defect is well 

 illustrated in districts where a stallion with only one testicle 

 visible is allowed to be used at stud. It is possible, too, that 

 atavism plays some part in this malformation, for I have met 

 with, at all events, two authenticated instances in which the 

 tendency appeared to come from the mare's side (see Appendix, 

 page 64). 



Power of Procreation. — When one testicle is visible the 

 animal may be quite as good a stockgetter as when both are 

 present, but when this has been removed, or when the testes 

 are in the inguinal canal or the abdomen, the probability is 

 that (although the sexual instinct is very marked) the animal 

 is unable to propagate its species. When examined micro- 

 scopically after removal it is not rare to find spermatozoa 

 in testicles which have remained in the lower part of the in- 

 guinal canal, but in those found in the upper part, and in those 

 taken from the abdomen itself, this is exceptional. 



In fourteen, instances Professor M'Fadyean reported upon 

 testes which I had taken from the abdomen, and spermatozoa 

 were discovered twice. In eleven testes taken from the in- 

 guinal canal five contained spermatozoa. Three of these were 

 at the extreme upper portion of the canal, and all were beyond 

 dispute in such a position that they could be termed " inguinal " 



1 "Journal of Comparative Pathology and Therapeutics," Vol. XIII., page 75. See 

 Appendix cases 27 and 50. 



