31 



Spermatozoa : Spermatozoa, the essential germinal elements, 

 are very frequently abnormal, changes in which may be manifested 

 in many ways. We may divide the deviations into changes in 

 structure, and changes in the motility which is so indicative 

 of the intrinsic vitality of the sperm. Reynolds (34) describes 

 two forms of abnormal motion. The first is " rotary swim- 

 ming," in which the sperms move forward progressively, and 

 sometimes with fair rapidity, but in a spiral screwlike manner, lie 

 states that this type of swimming is very awkward, easy to recog- 

 nize, and is usually of quite long duration. The other form termed 

 "pendulum swimming," he slates, is less common than the rotary 

 swimming and is usually confined to relatively fewer sperms in a 

 given field. "In this the middle piece and upper tail seem to lose 

 their flexibility and balance to a considerable degree, and the 

 lower tail motion swings the forward part of the spermatozoon to 

 and fro with a pendulum movement. This type oi: swimming yields 

 very poor progress." 



One factor we must bear in mind in the study of the semen ob- 

 tained from the vagina, is that the spermatozoa may be highly 

 motile before ejaculation, but the admixture of hostile vaginal 

 mucus may inhibit or destroy the motility. On the other hand, 

 the conditions may be reversed. Gary (35), in one instance, 

 found that the spermatozoa in a sample of semen collected from a 

 condom, appeared to be of very low vitality, Avhile when thej^ were 

 mixed with the vaginal secretions, an (exaggerated activity was 

 manifested. INIay we not have to contend with this factor in some 

 herds in which there is a very distinct 'acid and toxic vaginal 

 secretion from the products of cervicitis and vaginitis'? 



In a study of motility, we must consider not only the abnormal 

 types which may be encountered but the percentage of motile cells, 

 and the duration of the movement. In nccrospcrmia all the 

 ejaculated cells are motionless or dead. In other specimens, vary- 

 ing percentages of the cells are without motion, and the others may 

 be possessed of full and lasting motility. On the other hand, the 

 motility in some eases is veiy active at first, Init quickly subsides 

 even undin* the best of conditions. The appearance in freshly 

 ejaculated semen of numerous sperms that have a tendency to take 

 on the "undulatory tactile" type of motion when they should be in 

 a hitxhly active state, is very indicative of lowered vitality. Many 

 specimens present this very picture, whereas the very active pro- 

 gressive movement should, under proper conditions, survive for a 

 considerable time before it gives way to the second, and slower 

 type. The cells frequently enrly bunt into epithelial cells or cUimps 

 of immotile sperms, then back out and move around sluga'ishly, 

 only to repeat the same performance till they stop moving en- 

 tirely. I have seen one specimen in which the sperms all tended 

 to clump. Whether this was the result of some agglutinative sub- 

 stance in the vaginal secretion is problematical. I have seen several 

 specimens of semen in which practically all the sperms were motile 



