AGGLUTINATION OF SPERMATOZOA. 



275 



the solution equal in specific gravity and hydrogen-ion concentra- 

 tion to sea- water, concentrated sea-water and N/ioo NaOH were 

 added. Controls were arranged by adding to glass distilled water 

 concentrated sea- water and N/ioo HC1. In making the correc- 

 tions I used a standard hydrometer, and a set of standards pre- 

 pared by Hynson, Westcott, and Dunning for determining the 

 hydrogen-ion concentration of sea-water. 



3. HETERO- AGGLUTINATION OF SPERMATOZOA OF Katharina 



tunicata. 



A. Effect of Solutions of Cytolyscd Spermatozoa of S. pur pur at us. 



The spermatozoa of K. tunicata, inactive in sea-water, are in- 

 tensely activated and agglutinated by solutions of cytolyzed sper- 

 matozoa of 5*. purpuratus. The reaction resembles iso-agglutina- 

 tion in this species in the formation of three-dimensional pinwheels 

 and differs from it only in the irreversibility of the hetero-aggluti- 

 nation (Plate I.). In forty-five experiments, in which two dif- 

 ferent test solutions were employed over a period of 34 days, 

 similar results were obtained. A single experiment will illustrate 

 the characteristics of the reaction. 



E.vp. 511. Material: K. tunicata spermatozoa; solution of cytolyzed sper- 

 matozoa of S. purpuratus. 

 3-21/21 2.23 P.M. 



As indicated above, the formation of pinwheels occurs after a 

 latent period of i l / 2 minutes in this experiment. In other experi- 

 ments the latent period was often shorter, but in no case less than 

 20 seconds. 



tilled water from 35 hours caused activation but no agglutination. This 

 may be due to an unstable property of the hetero-agglutinating substance 

 in distilled water. 



