SPERM AGGLUTINATION AND FERTILIZATION. 



FRANK R. LILLIE. 



In a recent paper on "Cluster Formation of Spermatozoa 

 Caused by Specific Substances From Eggs" Loeb ('14) has pre- 

 sented a criticism of my theory of fertihzation (Lillie '13& and 

 '14), based on observation of the California sea-urchin Stron- 

 gylocentrotus purpuratus. My own observations were made on 

 Arhacia punctulata of Massachusetts, and it would appear that 

 part at least of Loeb's criticism was due to certain differences in 

 the two forms, for he has now stated (Loeb, 191 46, p. 318, foot- 

 note) that the "cluster formation" of the spermatozoa may find 

 its explanation "on the assumption of an agglutination at least 

 in the case of Arhacia,'" as I maintained; it is therefore not a 

 "tropistic reaction" as he thought probable from his observa- 

 tions in California. This was one of the chief differences of 

 opinion. A second one was in regard to the source and sig- 

 nificance of the substance in the fluid of e^g suspensions that 

 caused such agglutination ; Loeb maintained that it was merely 

 the dissolved chorion {i. e., jelly layer) of the egg, and that after 

 this was removed the eggs no longer produced the agglutinating 

 substance, and yet were capable of fertilization; whereas my 

 contention was that the agglutinating substance was a secretion 

 of the egg soaked up by the jelly, as by a sponge; that the eggs 

 produced it for a certain length of time after the removal of the 

 jelly, and lost their power of fertilization after they ceased to 

 produce it. 



These criticisms cut at the foundation of my theory. Inas- 

 much as the correction of the tropistic interpretation of agglutin- 

 ation is given only in a footnote to another paper, and no cor- 

 rection of the source of the agglutinating substance has yet 

 appeared, it is incumbent on me to consider the criticisms 

 carefully; at the same time I wish to take the opportunity to 

 explain certain points that appear to be open to misinterpretation, 

 and to record some new observations. 



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