22 FRANK R. LILLIE. 



arachnws, and has shown a constant relationship of a very 

 definite sort between fertilizin content of the eggs as shown by 

 the agglutination reaction and their capacity for fertilization. 



The measurements of specificity contained in the present paper 

 are interpretable in the same way. One cannot regard the spe- 

 cificity in fertilization and in sperm agglutination as unrelated 

 phenomena. The change in the spermatozoon produced by the 

 fertilizin of its own species must in some way be connected with 

 the relative ease with which the spermatozoon fertilizes the egg 

 of its own species. The fertilizin theory gives a reasonable view 

 of this relationship. The variable percentages of cross-fertiliza- 

 tion would show that a degree of reaction which would not 

 suffice for agglutionation of the spermatozoa may yet be suffi- 

 cient under favorable circumstances for activation of fertilizin. 



LITERATURE. 

 Just, E. E. 



'19 The Fertilization Reaction in Echinarachnius parma. I. Cortical Re- 

 sponse of the Egg to Insemination. II. The Role of Fertilizin in 

 Straight and Cross Fertilization. III. The Nature of the Activation of 

 the Egg by Butyric Acid. BIOL. BULL., Vol. 36, pp. 1-53. 

 Lillie, Frank R. 



'13 Studies of Fertilization. V. The Behavior of Spermatozoa of Nereis 

 and Arbacia with Special Reference to Egg-extractives. Journ. Exp. 

 Zool., Vol. 14. 



'14 Studies of Fertilization. VI. The Mechanism of Fertilization in Ar- 

 bacia. Journ. Exp. Zool., Vol. 16. 



'19 Problems of Fertilization. The University of Chicago Press. 

 Loeb, J. 



'14 Cluster Formation in Spermatozoa caused by Specific Substances from 

 Eggs. Journ. Exp. Zool., Vol. 16. 



'15 On the Nature of the Conditions which Determine or Prevent the 

 Entrance of the Spermatozoon Into the Egg. Am. Nat., Vol.49, pp. 

 257-285. 

 Moore, C. R. 



'16 On the Superposition of Fertilization on Parthenogenesis. BIOL. BULL., 

 Vol. 31. 



'17 On the Capacity for Fertilization after Initiation of Development. 



BIOL. BULL., Vol. 32. 

 Richards, A., and Woodward, A. E. 



'15 Note on the Effect of X-Radiation on Fertilizin. BIOL. BULL., Vol. 28. 



