47 



with sluggish motility are always low in vitality, and have weak 

 powers of insemination, as the motion lasts but a comparatively 

 short time. The vitality may be but moderately lowered, so that 

 although the sperms are highly motile when ejaculated they soon 

 lose their power of propulsion. The type of motion is likewise an 

 indicator of lack of vitality. The '"progressive vibratilc" motion 

 described by Reynolds should proceed to a high degree for a long 

 period before the "undulatory tactile" or bunting types of motion 

 appear. Early appearance of these two latter ty])es indicates in 

 most eases a marked lack of vitality of the elements. The motion 

 should be vigorous and lasting, for, as stated by Reynolds, "noth- 

 ing is more certain than that spermatozjoa of merely moderate 

 vitality seldom impregnate a female." 



The early precipitation out of the "Boettcherchen" crystals is 

 very characteristic of oligospermia, and impotent semen. The 

 theory here is that crystals do not precipitate out wdien a fluid i-^ 

 actively moving, but soon do so when the fluid is motionless. The 

 sediment which normally makes up about two-thirds of the sample 

 is usually decreased in abnormal samples. The semen itself should 

 be observed for unusual viscosity or a thin watery condition. 

 Clotting should occur readily after emission, but the clot soon 

 liquefies to some extent, allow'ing the spermatozoa to become more 

 active. This clotting is, of course, to protect the delicate spei-ms 

 from the hostile secretions of the vagina. 



The presence of immature and deformed types of sperms rep- 

 resents some disturbance of spermatogenesis, but it is difficvilt to 

 explain the significance of these forms. They are seldom seen in 

 normal samples, and undoubtedly none are capable of producing 

 impregnation. In the case of minor abnormalities of staining rf- 

 actions. the sperms are probably deficient in nuclear material or 

 othei-wise altered so that probably they are incapable of reaching 

 and uniting with the ovum. When impregnation does occur in 

 the.se cases, weak offspring undoubtedly result in many instances. 



The work has by no means progressed to the point where one 

 may. by an examination of the semen, determine the degree of 

 impotency with great accuracy, or even whether the animal may 

 be restored to sexual health by proper hygienic and therapeutic 

 treatment. Ivelatively, the greater the changes in the semen and 

 spermatozoa, the less the chances of impregnation. Infertility 

 to any marked degree, is, however, usually accompanied by cor- 

 responding ehanges in the seminal fluid and its germinal elements. 



Examination of the semen is, and pro])ably always will be. 

 simply an aid in reaching a diagno.sis. AVhile abnormalities of 

 the semen and spermatozoa are associated Avith sterility or in- 

 fertility, it is unwise to lay too much emphasis upon this method 

 of diagnosis alone, especially Avith regard to the making of a 

 definite prognosis. When large numbers of abnormal spermatozoa 

 are present in the semen, we are safe in saying that the animaJ 



