'64 CASTRATION OF CRYPTORCHID HORSES. 



Fertility.— That there may be spermatozoa in those found 

 even some distance up the inguinal canal is shown by Nos. 

 48, 56, 62, 66, and 70, and Nos. 19 and 49 are of especial 

 interest because they were taken direct from the abdominal 

 cavity, and Professor M'Fadyean discovered spermatozoa in 

 them. The presence of spermatozoa, however, does not 

 necessarily imply fertility, as they may be immature 

 specimens, or too few in numbers. 



Colt No. 56 was known to have served a mare three months 

 before the operation, and spermatozoa were demonstrated from 

 the right (inguinal) testicle, but she proved barren. 



Heredity. — Nos. 20 and 21, 5 years and 3 years old 

 respectively, each with an undescended abdominal testicle, 

 were out of the same mare, but by different sires. Curiously 

 enough, too, there was the coincidence of both being on the 

 right side. Both the sires were well developed, and no more 

 "rigs" have been got by them in the neighbourhood. The 

 dam has only had one other foal, that being a filly. The 

 mare has no known "rig" relatives but her two offspring. 



Nos. 15 (2 years old, inguinal), 16 (5 years old, left 

 abdominal), and 38 (7 years old, right abdominal) were by the 

 same stallion, out of different mares. The dam of No. 15 

 only bred two colts and both were " rigs." They were by the 

 same sire. This sire, a cart stallion, has been in the present 

 owner's possession for 12 years. He is decidedly not a " rig," 

 nor has he any known " rig " relatives except as regards his 

 own colts. With reference to them the owner wrote me, " We 

 have bred quite 1 5 colts from this particular sire, and 4 of these 

 were " rigs." We have heard of no " rig " colts amongst the 

 stock of the other farmers who have used him as a stallion. 

 We have the stallion now; he is a sure foal getter although 17 

 years old." 



The fact that two out of the four were from the same mare 

 is certainly, when added to Nos. 20 and 21, worth special 

 observation. 



