PHYSIOLOGY OF THE SPERMATOZOON 119 



the capacity of Arbacia eggs to continue the production 

 of the agglutinating substance for a long period of time 

 after removal of the jelly has been demonstrated. 

 Glaser (1914) obtained the same result. To obtain 

 clear evidence of the reaction from such eggs the obser- 

 vations must be made under the microscope, preferably 

 by the raised cover-slip method, immediately after addi- 

 tion of the egg water, for the reaction lasts only from 

 five to fifteen seconds and the agglutinations are micro- 

 scopic in size. It would appear probable from Loeb's 

 account that he used only macroscopic methods, and 

 this may be the reason for his negative statement 

 concerning Strongylocentrotus. 



The case of immature eggs also shows that the 

 agglutinating substance is distinct from the jelly, be- 

 cause these eggs are already provided with jelly, but 

 egg water from them contains no agglutinating sub- 

 stance. It would therefore appear that this substance 

 begins to be produced during the process of maturation 

 of the egg and is discharged from the egg into the jelly, 

 which becomes saturated with it, and will therefore 

 continue to yield it up to sea-water even when sepa- 

 rated from the egg. These results are completely 

 confirmed by Just (1919) for Echinarachnius. 



The agglutination is between the heads of the sper- 

 matozoa, which obviously become adhesive as a result 

 of action of the egg water; the tails of the spermatozoa 

 are apparently unaffected; the adhesive change, how- 

 ever, soon passes away, hence the subsequent reversal 

 of agglutination. The loss of adhesive properties may 

 be due to solution of the adhesive substance in the 

 sea-water or to a physical change in the substance. 



