AGGLUTINATION OF SPERMATOZOA. 



279 



4. HETERO-AGGLUTINATION OF SPERMATOZOA OF 5\ purpuratus 

 AND OF S. franciscanus BY THE BLOOD OF Katharina 



tunicata. 



Since spermatozoa of K. tunkata were agglutinated by the 

 blood and by solutions of cytolyzed spermatozoa of 5". purpuratus 

 and by the blood ot S. franciscanus, it seemed possible that the 

 relationship might be reciprocal. This proved to be the case, but 

 the type of hetero-agglutination obtained resembles that described 

 by Lillie as " mass coagulation." A single protocol will illustrate 

 the nature of the reaction. 



E.\-p. 585. Blood of K. tunicata; spermatozoa of 5". purpuratus, 

 5/4/21 2.15 P.M. 



As indicated, there is no ring formation due to aggregation. 

 The spermatozoa rapidly form strands which adhere to one an- 

 other, and lose their motility. This hetero-agglutination is com- 

 pletely irreversible and decidedly toxic. It is of interest that the 

 blood of K . tunicata which causes hetero-agglutination of sperma- 

 tozoa of S. purpuratus and of 5". franciscanus also causes mem- 

 brane formation in the eggs of these two species. If allowed to 

 act too long, it will induce cytolysis. A short treatment followed 

 by a brief exposure to hypertonic sea-water will, however, lead to 

 parthenogenetic development of the ova of S. franciscanus, Samp- 

 son (unpublished). 



5. HETERO-AGGLUTINATION IN OTHER ECHINODERMS AND 



MOLLUSCS. 



Tests were made with the spermatozoa of other Echinoderms 

 and Molluscs to demonstrate hetero-agglutination. The results of 

 these tests indicate two distinct types of hetero-agglutination: (A) 

 the toxic "mass coagulation," described by Lillie for Nereis 

 spermatozoa; (5) the pinwheel type, described in this report for 



