564 FRANK R. LILLIE 



The fact that the egg secretions of Arbacia cause agglutination 

 of Nereis sperm as well as Arbacia sperm seems at first sight 

 to indicate the iso-agglutinating substance of Arbacia is not 

 specific. But the fact that other Arbacia fluids likewise aggluti- 

 nate the sperm of Nereis, but not those of Arbacia, raises the 

 question whether the egg-secretion does not contain in addition 

 to the iso-agglutinating substance, also another which is aggluti- 

 native for Nereis sperm like the substance in the coelomic fluid, 

 but not for its own sperm. 



If there are two substances present in the egg secretion it ought 

 to be possible to separate them by various means. They might 

 exhibit different heat-labihty, so that one might be destroyed at 

 a temperature that would leave the other still active. Of if they 

 have different affinities it might be possible to fix the Nereis agglu- 

 tinating substance by Nereis sperm, leaving the iso-agglutinating 

 substance intact. Neither of these experiments could be per- 

 formed this year, owing to the disappearance of the necessary 

 material. 



However, it was possible to show in another way that the Nereis- 

 agglutinating substance of Arbacia egg-extract is distinct from the 

 iso-agglutinating substance: An egg-extract of Arbacia seventeen 

 days old was found to have entirely lost its power of agglutinating 

 Nereis spermatozoa, while it retained undiminished its power of 

 agglutinating Arbacia spermatozoa. Originally it agglutinated 

 both kinds of spermatozoa. Now the change that took place in 

 the egg-extract on standing is not a mere weakening of action as 

 might be supposed, because the iso-agglutinating action was 

 noted as undiminished, whereas the hetero-agglutinating action 

 was entirely lost. The only possible conclusion, therefore, is 

 that the egg-extract contained two agglutinating substances at 

 least, namely: An iso-agglutinin and a hetero-agglutinin, and 

 that the latter is relatively labile, the former relatively stable. 

 Unfortunatelly the experiment could not be repeated on account 

 of the total disappearance of the material. 



fact, an almost necessary conception on the general principles of immunity phe- 

 nomena that the sperm should so act. The question would be, of course, whether 

 there is a connection between any antibodies so formed and the sperm iso-agglu- 

 tinins produced by the next generation of ova. 



