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- 

 tozoon," Zeitschr. fur 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., XL VI, 

 145-76. 



COHN, EDWIN J. 



1917. "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," B-iol. 

 B ulL, XXXIV, 167-218. 



DEWITZ, J. 



1885. "Ueber die Vereinigung der Spermatozoen mit dem 

 Ei," Arch, fur d. ges. PhysioL, Band 37, pp. 219-23. 



1886. "Ueber Gesetzmiissigkeit in der Ortsveranderung 

 der Spermatozoen und in der Vereinigung derselben 

 mit dem Ei," ibid., Band 38, pp. 358-85. 



DUNGERN, EMIL VON. 



1902. "Neue Versuche zur Physiologic der Befruchtung," 

 Zeitschr. filr allgem. PhysioL, Band I, pp. 34-55. 

 See also CentralblaU fur PhysioL, 1901. 



GEMMIL, JAMES J. 



1900. "On the Vitality 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 Arbacia and Asterias," Biol. Bull., XXVI, 

 367-86. 



