AGGLUTINATION OF SPERMATOZOA. 



273 



Lepasterias a quails, Astcrias forbesii; Ishnochiton mag dal en en sis, 

 Mopalia muscosa, Crypto chit on, Abalonc, and Cumingia. Both 

 sperm and ova were ripe. 



Activation occurred in every case, but no agglutination com- 

 parable to that in sea-urchins, Nereis or K. tunicata. In Astcrias 

 forbesii, Astcrias ochracca, and Cumingia irregular clumps form 

 consisting of a few spermatozoa. These, however, are irregularly 

 dispersed and hence do not correspond to those which appear pre- 

 ceding typical iso-agglutination. 



TABLE I. 



THE EFFECTS OF EGG-WATER ON SPERMATOZOA OF THE SAME SPECIES. 



6. DISCUSSION. 



The variation in character of the iso-agglutination reaction may 

 be due in part to the degree of motility of the spermatozoa in- 

 volved. Swarming is obtained with spermatozoa highly motile in 

 sea-water; the pinwheel type with spermatozoa inactive in sea- 

 water (K. tunicata), or with spermatozoa rendered less active in 

 sea-water by staling (Arbacia). The fact that spermatozoa of 



