I 26 PROBLEMS OF FERTILIZATION 



chemotaxis, as others have supposed. It appears really 

 to be a more complex event in which the various forms 

 of behavior of the spermatozoon may all play a part, 

 as indicated. 



REFERENCES 

 Ballowitz, Emil. 



1890. " Untersuchungen ueber die Structur der Sperma- 

 tozoen," Zeitschr. fiir wiss. Zool. (See pp. 392-93). 



BULLER, A. H. 



1902. "Is Chemotaxis a Factor in the Fertilization of the 

 Eggs of Animals?" Quart. Jour. Micr. Set., XLVI, 

 145-76. 

 CoHN, Edwin J. 



191 7. "The Relation between the Hydrogen Ion Concen- 

 tration of Sperm Suspensions and Their Fertilizing 

 Power," Anat. Rec, II, 530. 



1918. "Studies in the Physiology of Spermatozoa," Biol. 

 Bull., XXXIV, 167-218. ^ 



Dewitz, J. 



1885. "Ueber die Vereinigung der Spermatozoen mit dem 

 Ei," Arch, fiir d. ges. Physiol., Band 37, pp. 219-23. 



1886. "Ueber Gesetzmassigkeit in der Ortsveranderung 

 der Spermatozoen und in der Vereinigung derselben 

 mit dem Ei," ibid., Band 2)^, pp. 358-85. 



DuNGERN, Emil von. 



1902. "Neue Versuche zur Physiologie der Befruchtung," 

 Zeitschr. fiir all gem. Physiol., Band I, pp. 34-55. 

 See also Centralblatt fiir Physiol., 1901. 



Gemmil, James J. 



1900. "On the VitaHty of the Ova and Sperm of Certain 

 Animals," Jour, of Anat. and Physiol., XXXIV, 163. 



Glaser, Otto. 



1914. "A Qualitative Analysis of the Egg Secretions and 

 Extracts of Arhacia and Asterias,^' Biol. Bull., XXVI, 

 367-86. 



