A zoo sperm ie 125 



I. AZOOSPERMIE. 



In the rearing and selection of male breeding aninaals, it be- 

 comes of importance to determine at the earliest possible date 

 whether they may prove efficient sires or not and it is essential, 

 first, to know whether they possess normal testicles capable of 

 producing vigorous spermatozoa. 



Although these organs, derived from the Wolffian bodies, are 

 formed in the sublumbar region, they normally descend into the 

 scrotum in all our domestic animals except the elephant and are, 

 consequently, with the one exception, quite freely available for 

 physical examination. 



In our large herbivorous animals, these organs normally de- 

 scend into the scrotum prior to birth, so that, when one of these 

 is born without this having occurred, that fact may well become 

 an object for suspicion. 



1. Anorchidy. In some cases these organs are entirely want- 

 ing or have been arrested in their development so that they are 

 wholly insignificant and devoid of physiologic power. Such ani- 

 mals fail to develop sexual desire in the least, do not acquire the 

 usual characters of the male in conformation, head, neck, horns, 

 voice, or other attributes, but remain neuter or asexual in char- 

 acter save in respect .to the penis and sheath and even these may 

 be defective. hMh testicles are present in the scrotum and none 

 are distinguishable by rectal exploration. On post-mortem ex- 

 amination, one may find within the abdomen a mass of tissue 

 which, by its attachments and relations, is identifiable as the rep- 

 resentative of the testicle, but devoid of any tissue of a true geni- 

 tal character. Such are the findings in some twin calves, as 

 well as in some single births, and the same conditions are met, 

 far more rarely, among other animals. 



2. Congenital Tumors. In other cases, instead of the normal 

 glandular tissue, the male animal is born with a tumor represent- 

 ing the genital gland, which may be either teratologic or patho- 

 logic. Among the teratologic, the most common are dermoid 

 cj'sts, containing hair, teeth and epithelial debris, along with 

 more or less fluid. 



A possible mode of origin of these structures has already been 

 discussed on page 12. 



In other animals, the primitive gland may become the seat of 



