96 The Biochemistry of Semen 



androgamone III ('egg-surface liquefying agent', 'sperm lysin') dis- 

 covered by Runnstrom and his co-workers and shown to be a heat- 

 stable alcohol-soluble substance, probably a fatty acid (p. 71). The 

 other is the protein-like jelly-coat 'dissolving' or 'precipitating' 

 factor, identical with Hartmann's androgamone II; the disappearance 

 of the egg-jelly under the influence of this protein-factor was origin- 

 ally described by Hartmann and his colleagues in Arbacia pustulosa, 

 but a similar phenomenon was later observed in other sea-urchin 

 species as well (Tyler and O'Melveny, 1941; Monroy and Ruff'o, 

 1947; Kraus, 1950; Vasseur, 1951; Monroy and Tosi, 1952). The 

 suggestion has been put forward that the agent which helps the sea- 

 urchin sperm to penetrate the jelly-coat, is a mucopolysaccharase 

 similar even though not identical, with hyaluronidase. This hypo- 

 thesis, however, is in want of experimental support. It is also difficult 

 as yet, to assign any definite role in fertilization to the proteolytic 

 gelatm-liquefying enzyme which Lundblad (1950) extracted from 

 the sperm of Arbacia lixula and Paracentrotus lividus. 



In mammals, the existence of an enzymic 'cumulus-dispersing 

 factor' was first brought to light by Yamane (1935), Pincus (1935) 

 and Pincus and Enzmann (1936) who showed that both sperm 

 suspensions and extracts from rabbit spermatozoa, brought in 

 contact with unfertilized rabbit ova, can disperse within a short 

 time the follicle cells of the cumulus oophorus. In 1942, McClean 

 and Rowlands discovered that hyaluronidase which they obtained 

 not only from testes or spermatozoa, but also from snake venom 

 and bacteria, can act as a cumulus-dispersing factor by liquefying 

 the viscous gel which cements the follicle cells around freshly ovu- 

 lated rat ova. Similar results on the mouse were reported by Fekete 

 and Duran-Reynals (1943) who also noted that the gel of the 

 cumulus responds to metachromatic staining with toluidine blue 

 like hyaluronic acid. 



It remains one of the unsolved mysteries in the phenomenon of 

 fertilization that although the actual fertilization consists ultimately 

 of the fusion of a single spermatozoon with the ovum, this can take 

 place apparently only after a multitude of spermatozoa have reached 

 the site of fertilization. Moreover, the denudation of the ovum from 

 follicular cells has also been claimed to require the presence of 

 numerous spermatozoa. According to McClean and Rowlands 



