136 WALTER LAWRENCE. 



efferentes, which become smaller toward the base of the epi- 

 didymis. These tubules in a sexually mature male are normally 

 distended with spermatozoa which are suspended in a viscous 

 matrix. On opening one of these normal tubules the contents 

 exudes as a thin white paste-like substance which on microscopic 

 examination reveals innumerable spermatozoa; these cells are 

 usually immotile until a drop of physiological saline solution is 

 added, when they are activated to rapid motility. Anderson 

 ('22) in a series of experiments on the spermatozoa of various 

 domesticated animals finds that sperm are normally immotile 

 until they are activated by the accessory secretions of the 

 reproductive system, but that the same results may be obtained 

 by adding normal saline. Armstead ('25) working with guinea 

 pigs finds sperm are made motile by addition of exudate from 

 the seminal vesicles which action he attributes to the alkalinity 

 of the exudate. I have observed slight motility in freshly 

 expressed spermatozoa, even before the saline was added but 

 this was a weak vibratile motion. When the saline is added 

 the spermatozoa became very motile, and are seen to swim 

 about in the medium in groups of from two to eight or ten, the 

 heads being cupped together, not unlike the condition seen in 

 blood where the erythrocytes have a tendency to form rouleaux. 

 In this stacked condition the flagella point in the same direction, 

 but there appears to be no rhythm in the motion of the flagella, 

 some vibrating vigorously and some little or none at all; as a 

 consequence the locomotion of these sperm groups is slow and 

 cumbersome, particularly so in the larger groups. 



In a cross section of the normal epididymis of the guinea pig 

 the tubules are all seen to contain a greater or less number of 

 spermatozoa with a marked tendency for agglutination as already 

 described. The ductus epididymis contains a mass of sperm 

 usually centrally located; the ductuli efferentes are more com- 

 pletely filled and the ampulla; of these tubules are thin walled 

 sacs well distended with sperm. The ductus deferens, likewise 

 contains a large number of sperm throughout its course. 



Epididymis of Six Days Abdominal Retention. Macroscopically 

 the epididymis of a six-day abdominally retained testis shows 

 slight differences in size and color from the normal. It is slightly 



