226 PROBLEMS OF FERTILIZATION 



TENNENT, DAVID H. 



1910. "Echinoderm Hybridization," Pub. No. 132, Carne- 

 gie Institution, Washington (other references to same 

 author here). 

 VERNON, H. M. 



1900. " Cross-Fertilization among the Echinoidea," Arch. 



jilr Entwickelungsmcch., Band 9, p. 464. 

 WALDSTEIN UND ECKLER. 



1913. "Der Nachweis resorbierten Spermas in weiblichen 

 Organismus," Wiener kiln. Wochenschrift, Jahrg. 26, 

 p. 1689. 

 WHITMAN, C. O. 



1891. " Spermatophores as a Means of Hypodermic Im- 

 pregnation," Jour, of M or ph., Vol. IV. 



