The Two Components of Semen 5 



which take place during spermatogenesis is defective and rests almost 

 entirely on histochemical observations. 



In several species so far investigated, spermatogonia and sperma- 

 tocytes have been shown to have a cytoplasm which is basophilic, 

 in distinction to mature spermatozoa which exhibit only a faint 

 coloration of the flagellum. Cytochemical studies carried out by 

 Brachet (1944, 1947) have shown that the affinity of the sperma- 

 togonia and spermatocytes for basic dyes is due to ribonucleic acid, 

 and cytochemical as well as spectrophotometric studies (Caspersson, 

 1939) point to the fact that spermatogenesis involves a progressive 

 disappearance of ribonucleic acid from the developing sperm cell. 

 In ejaculated spermatozoa of the bull, Vendrely and Vendrely (1948) 

 using the analytical methods of Schmidt and Thannhauser (1945) 

 and Schneider (1945), found a content of 0-2x1 0~^ mg. ribonucleic 

 acid per sperm cell, that is fifteen times less than the corresponding 

 value for deoxyribonucleic acid. An analysis of mature ram sperma- 

 tozoa carried out in our laboratory with the Markham-Smith 

 chromatographic procedure (1949) which is based on the identifica- 

 tion of uridylic acid in an acid hydrolysate of ribonucleic acid, 

 failed to reveal the presence of uridylic acid. As to the origin of 

 ribonucleic acid in the spermatogonia and spermatocytes, a study of 

 the spermatogenesis in Asellus aquaticus (Vitagliano and de Nicola, 

 1948) suggests that ribonucleic acid is not elaborated in the develop- 

 ing gametes themselves but is secreted by the surrounding cells and 

 then absorbed and utilized by the germ cells. 



Two other processes associated with spermatocytic development 

 are: the progressive decline of alkaline and acid phosphatase activity 

 (assessed histochemically) in the nuclei (Krugelis, 1942; Wolf, Kabat 

 and Newman, 1943), and a simultaneous disappearance of glycogen. 

 Both the Sertoli cells and the spermatogonia abound in glyco- 

 gen, which also occurs, although in a smaller concentration, in the 

 primary spermatocytes (Montagna and Hamilton, 1951; Elftman, 

 1952; Long and Engle, 1952; Mancini, Nolazco and Baize, 1952). 

 But the secondary spermatocytes and the spermatids give practically 

 no cytochemical reactions for glycogen, and in the mature sperma- 

 tozoa the glycogen content is exceedingly low: in ejaculated ram 

 semen 'glycogen' content, i.e. the alkali-resistant polysaccharide 

 which behaves like glycogen on ethanol-precipitation and which 



