SPERMATOZOIDS. 



Y91 



FIG. 288. Spermatozoids, spermatic crystals, leuco- 

 cytes etc. (Peyer). 



ply as a vehicle for the introduction of these bodies into the generative 



passages of the female. 



Spermatozoids. In August, 1677, a German student, named Von Ham- 



men, discovered the spermatozoids in the human semen and exhibited them 



to Leeuwenhoek, who studied them 



as closely as was possible with the in- 



struments at his command. For a 



long time they were regarded as liv- 



ing animalcules, although now they 



are considered simply as peculiar, 



anatomical elements endowed with 



movements, like ciliated epithelium. 



These elements are developed within 



the seminiferous tubes ; and they 



differ, not so much in their mode of 



development, as in their form, in 



different animals. 



The fluid taken from the vesiculae 



seminales of an adult who has died 



suddenly or the ejaculated semen 



contains, in addition to the various 



accidental or unimportant anatomical elements that have been mentioned, in- 



numerable bodies, resembling animalcules, which present a flattened, conoidal 

 head and a long, tapering, filamentous tail. The tail is 

 in active motion, and the spermatozoids move about the 

 field of view with considerable rapidity and force, pushing 

 aside little corpuscles or granules with which they may 

 come in contact. Under favorable conditions, particularly 

 in the generative passages of the female, the movements 

 may continue for several days. 



Microscropical examination does not reveal any very 

 distinct structure in the substance of the spermatozoids. 

 The head is about ^^5- of an inch (5 /A) long, -^^ of an 

 inch (3 /A) broad, and 2 sooo of an inch (1 /x,) in thickness. 

 The tail is about -5^-5- of an inch (50 /A) in length. La 

 Vallette St. George has found in man and many of the in- 

 ferior animals the " intermediate segment " described first 

 by Schweigger-Seidel, though he does not agree with 

 Schweigger-Seidel that this portion is motionless. The 

 length of the intermediate segment is about 4o * o6 of an 

 inch (6 /A). It usually is described as the beginning of the 

 ^1 an( ^ ^ ne only difference between this and other por- 

 dia eter8 tions is that it is a little thicker. At the extreme end, is 



i, flat view ; 2, side a short and excessively fine filament, called the terminal 



view ; A A, head; B B, ,,1 



intermediate seg- nlament. 



terminal filament! ' Water speedily arrests the movements of the sperma- 



