460 ALVALYN E. WOODWARD 



capillary pipette, into a suspension of sperm, the latter become 

 more active and gather around the drop as if chemically attracted. 

 In addition, they form small clusters, 'agglutinations,' which 

 last for several seconds. After this the sperm separate. The 

 period of agglutination depends upon the activity and density of 

 the sperm suspension and the strength of the egg-water. The 

 effective material in the water Lillie ('12) called an iso-agglutinin. 



The eggs of Nereis were found to produce a similar substance, 

 which seemed to appear at the moment of fertilization. In this 

 case, however, the active substance is destroyed by boiling, while 

 Arbacia agglutinin is not entirely destroyed when boiled for 

 seventy minutes. Lillie also found that an extract of Arbacia 

 eggs agglutinated Nereis sperm. Because of differences in la- 

 bility, he concluded that the Arbacia egg produced both iso- 

 and hetero-agglutinins. He also discovered that if sperm be 

 added in quantity to egg-water, the agglutinin is 'fixed,' and no 

 longer affects sperm subsequently added. 



For purposes of quantitative comparison, Lillie prepared a 

 'standard solution' of egg secretion by allowing one volume of 

 'dry' ripe eggs to stand in two volumes of sea- water for ten 

 minutes. During this time the eggs were occasionally agitated. 

 They were then precipitated with the centrifuge, and the super- 

 natant fluid, carefully decanted, was subsequently used (Glaser, 

 '14 c, p. 388). Since this secretion had such peculiar effects on 

 spermatozoa, and since eggs from which it had been removed by 

 repeated washings could not be fertilized Lillie has since called 

 it 'fertilizin' ('13 b). 



A substance to which the cell membrane is not permeable was 

 also found in the egg. This material could be obtained only by 

 laking with distilled water or crushing. Since this material was 

 able to neutrahze the agglutinative power of fertihzin, Lillie 

 cal ed it 'anti-fertihzin.' Antifertilizin does not prevent the 

 chemotactic effect of egg secretion. 



In addition, Lillie likewise discovered that Arbacia blood in- 

 hibits fertilization in the same species, but does not affect the 

 agglutinative power of fertilizin. Moreover, the inhibitory 

 effect of blood can be counteracted by an excess of fertihzin. 



