Malignant Tumors 243 



moner in geldings than in stallions. This relates especially 

 to the penis. Clinically, also, I have seen more malignant 

 neoplasms in the stumps of the spermatic cords of geldings 

 than in the testicles of stallions. It is possible that the es- 

 sentially dormant genitalia of emasculated animals are more 

 vulnerable to malignant new-growths. 



The testicle and epididymis of the stallion is only very 

 rarely the seat of malignant tumors. In one stallion I diag- 

 nosed clinically malignant disease of the testicle, but had 

 no opportunity to verify my diagnosis by direct examina- 

 tion of the gland. In the college collection there are no 

 specimens of malignant disease of the testicles of the horse. 

 When cryptorchidy occurs in man, it commonly raises the 

 question of malignant disease of the testicle. Although 

 cryptorchidy is very common in horses, the condition is 

 rarely, if ever, attributable to malignant disease. The clini- 

 cal diagnosis of malignant disease of the testicles is to be 

 made upon the same general basis as the diagnosis of malig- 

 nant tumors of other organs. 



When malignant disease of the testicle in the horse is se- 

 riously feared, the gland should be promptly removed for 

 the same reasons and in the same manner as already de- 

 scribed for the bull. 



Malignant disease of the testicles and epididymis in other 

 domestic animals is rarely reported. Clinically I removed 

 successfully a cryptorchid, cancerous testicle from a pig. 

 It was adherent over its entire surface to the adjacent in- 

 testines and mesentery, so that it had to be dissected away 

 carefully. 



Malignant disease of the penis, sheath, and prepuce in the 

 stallion is generally supposed to be common. At least, 

 writers upon veterinary surgery, as CadiotS Bayer and 

 Frohner=, and others, would lead the reader to believe so. 

 I have not observed a case in either penis, prepuce, or 

 sheath in a stallion, and my collection contains no specimen. 



1 Traite de Therap. Chir. d. Animaiix Doiiiestiques, 1898, p. 674. 



2 Handbuch d. Tier. Chir. u. Geburtsh., 1899, vol. iii, Part II, p. 345. 



