IS 



of the vaginal mucosa. This distri1)ution is rendered necessary 

 because some of tlie fluid flows from the vagina following coitus. 

 In this manner the opportuniiy is given for a part of the ejacu- 

 late containing the spermatozoa to be brought easier to the ex- 

 ternal OS, and (3) it happens that because of its content of sodium 

 chloride the life of the spermatozoa is stimulated and prolonged." 

 A fuller discussion of the essential physiology of the various parts 

 of the tract on the semen content, and fertility', Avill be taken up 

 later. The changes in biochemical content, reaction, and the re- 

 sult of the addition of bacterial products will also be more fully 

 discussed. 



Spermatozoa : The history of the discovery of spermatozoa 

 is very interesting, and for that reason a brief outline will be 

 given. The "semen threads" were first observed in the year 

 1667, bv Ham, a student of Leeuwenhoek at Levden. The dis- 

 covery was announced, confirmed by findings in the dog and 

 rabbit, and discussed by the latter author under the title : Ob- 

 servationes Anthonii L. de natis e semine genitali animaculis 

 (Upon the formation of young from procreative material). The 

 sperms were taken to ])e animals on account of their motility, and 

 their significance remained questionable if not unknown. Spal- 

 lanzi, quoted by ^Marshall (29), was the first to show that the 

 filtered fluid was impotent, and that spermatozoa in the semen 

 were essential to fertilization. Kolliker, in 1841. discovered that 

 the sperms arise from the cells of the testis, and Barry in 1843. 

 observed the conjugation of sperm and ovum in the rabbit. This 

 led to a clear understanding of the function of these important 

 germinal elements. 



The spermatozoa are the male procreative cells, and are cliar- 

 acterizecl by the possession of a head containing the chromo.somes 

 necessary for fertilization, and a tail capable of propelling the 

 organism on its way to meet the ovum. The length of the entire 

 sperm, including the head, is seventy-five to eighty microns. The 

 head is nine and five-tenths microns long, and five and five-tenths 

 microns wide. It may be divided into two principal parts, the 

 head and tail. The head, for the larger part, is made up of the 

 nucleus, and may be differentiated by staining reactions into a 

 darker staining posterior part, an anterior lighter part, and often 

 a still lighter area between the two. On the anterior part is a 

 sharpened edge, the acrosome, which serves to perforate the ovum. 

 The Avhole is surrounded by a very definite limiting membrane 

 which often becomes obscured under abnormal conditions. The 

 tail may be divided into three parts: connecting piece, principal 

 part, and terminal filament. The connecting piece, the essential 

 motile apparatus, is the thickest and strongest part, and joins the 

 tail p-roper to the head. It consists of the central axial filament, a 

 spiral filament around this, and an outer mitochondrial coverinsr. 

 Anteriorly it is limited by the anterior portion of the posterior 

 chromosome, and posteriorly liy the annular chromosome. The 



