98 The Biochemistry of Semen 



which act irreversibly, consist of heavy metals and quinones, includ- 

 ing certain quinoid compounds derived from flavonoids (Beiler and 

 Martin, 1947, 1948; Rodney et ai, 1950). Much interest was aroused 

 some time ago by a report that phosphorylated hesperidine, a 

 potent in vitro inhibitor of hyaluronidase, can act as an 'anti- 

 fertility factor' when administered to mice and human beings; 

 however, attempts to substantiate this claim have, so far, been un- 

 successful (Martin and Beiler, 1952; Sieve, 1952; Martin, 1953; 

 Chang and Pincus, 1953; Thompson, Sturtevant and Bird, 1953). 



Sperm nucleoproteins 



In the mature sperm cell, the sperm nucleus fills the head almost 

 completely, the surrounding cytoplasm being very scanty. This 

 nucleus consists of closely packed chromatin embedded in a rela- 

 tively small amount of nuclear sap. The first to investigate the 

 chemistry of the sperm nucleus was Miescher (1878, 1897) whose 

 pioneer studies laid a foundation for the modern developments in 

 the chemistry and physiology of the cell nucleus, the nucleoproteins 

 and the nucleic acids. As a result of Miescher's brilliant researches, 

 continued and extended by such investigators as Kossel, Schmiede- 

 berg, Burian, Levene, Steudel, Lynch, Hammarsten, Rasmussen and 

 Linderstr0m-Lang, and many others, it is now generally recognized 

 that the chief component of sperm chromatin, one which confers 

 upon the paternal (haploid) chromosomes their functions as trans- 

 mitters of inheritance, is by its chemical nature, a deoxyribonucleo- 

 protein^ and consists of deoxyribonucleic acid conjugated with cer- 

 tain basic nuclear proteins such as protamines and histones. 



Miescher used for his work chiefly salmon spermatozoa which he 

 obtained mostly by stripping the live fish. A considerable advantage 

 of this method is that the material thus obtained consists entirely of 

 ripe spermatozoa and is therefore of uniform composition. This 

 useful material, however, is not always procurable and is sometimes 

 replaced by whole excised fish testes which are less suitable as they 

 may contain some immature spermatozoa even during the breeding 

 season. Miescher's routine procedure was to remove first the 

 sperm-tails by plasmolysis with water or weak acetic acid and then 

 to treat the washed suspensions of sperm-heads with ethanol and 

 ether, to remove the lipids. In order to separate sperm nucleic 



