26 EGG AND SPERM SUBSTANCES 



the glycoprotein fertilizin, which specifically agglutinates sperm. 

 However, egg water has been reported to have a variety of other 

 effects on sperm as well. In some instances these effects have also 

 been attributed to fertilizin, but the possibility of action by other 

 agents has not always been eliminated. The effects of egg water 

 on sperm will be considered briefly before discussing fertilizin 

 and the antifertilizin from eggs. 



Effects of Egg Water on Sperm 



Chemotaxis and the Approach of the Sperm. When eggs are 

 inseminated, the sperm are frequently observed to accumulate in 

 the vicinity of the egg. This effect is particularly striking in spe- 

 cies whose eggs have a gelatinous coat, and it has led several 

 investigators (Lillie, 1913b; Hartmann, Kuhn, Schartau, and 

 Wallenfels, 1939; Vasseur and Hagstrom, 1946) to the view that 

 diffusible agents (including echinochrome ) from the eggs have 

 chemotactic action upon the sperm. Action of this kind appears 

 to be well established in certain mosses and ferns (see Roths- 

 child, 1951a, 1952, for recent account), but this effect has yet 

 to be demonstrated convincingly in metazoa. Sperm can be 

 shown to accumulate in capillary tubes containing egg water or 

 in drops of egg water injected into sperm suspensions. However, 

 as several investigators (Morgan, 1927; Rothschild, 1951a,b, 

 1952; Tyler, 1948a, 1955) have emphasized, the possibility of a 

 trap action on the sperai has not been eliminated in these ex- 

 periments. Such trap action could result from agglutination of the 

 sperm or a combination of factors affecting sperm motility (see 

 Rothschild, 1951b, for detailed discussion). In the absence of 

 independent evidence it must be concluded that chemotaxis 

 of metazoan sperm has not been demonstrated and that the sperm 

 probably approach the egg by random motion. Accumulation of 

 sperm about eggs is explained by an adhesion ( trapping ) of sperm 

 in the jelly or at the egg surface following chance contact. 



Effect of Egg Water on Sperm Motility ami Respiration. Sper- 

 matozoa of the sea urchin become intensely active in the vicinity 

 of eggs. This observation suggests that some product diffusing 

 from the egg activates the sperm. Lillie (1913b) confirmed this 



