SHORTER ARTICLES AND DISCUSSION 



THE DUALITY OF EGG-SECRETION 

 There are two' properties of egg-secretion which have attracted 

 particular attention. One of these is the power of agglutinating 

 spermatozoa (Lillie^) ; the other is the power of activating the 

 egg (auto-parthenogenesis, Glaser^). These effects have been 

 studied separately, but under normal conditions both must bear, 

 in close affiliation, upon the events of fertilization. 



We are still in the stage of hypothesis. AVe know that without 

 exudates fertilization does not take place. This was first demon- 

 strated by F. R. Lillie {loc. cit.), who removed the exudates. 

 These, as I found later, can be rendered ineffective without 

 removal, by the presence of charcoal.^ In neither case is fertiliza- 

 tion possible. We also know, from the investigations of Lillie, 

 that the agglutinating agent can be neutralized in two ways: 

 either by spermatozoa, or, by some derivative from the egg itself. 

 Inasmuch as fertilization is prevented by this derivative, Lillie 

 has called it " anti-f ertilizin. " 



Lillie also discovered that the blood of the sea-urchin (Arhacia) 

 has preventative effects, but these are different from those of 

 ''anti-fertilizin." There is in this case no interference with the 

 agglutination reaction ; yet the egg remains unactivated. 



Miss Woodward* and I (loc. cit.) have extended the list of 

 inhibitors to include such diverse things as the pigmented sub- 

 stances derived from testicular tissues; fatty and aqueous ex- 

 tracts of the eggs; and now, oleic acid and olive oil. However 

 I shall consider further only the inhibitors discovered by Lillie. 



II 



These, together with the fact tliat tlic exudates are necessary 

 in normal fertilization, are the foundations of the fertilizin 



2 Biological Bulletin, Vol. 26, pp. .387-409. 



* Journal of Experimental Zoology, Vol. 26, pp. 459-501. 



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