STUDIES IN THE PHYSIOLOGY OF SPERMATOZOA. 215 



inactive in egg water. Such egg water has a high hydrogen ion 

 concentration. Thi-s is reached as a result either of the carbon 

 dioxide produced by eggs and eliminated into the sea water, or 

 by spermatozoa during the period of their greatest activity. If 

 spermatozoa are added after they. have become inactive, the per- 

 centage of eggs that are fertilized depends upon the degree of 

 inactivity and the degree of reactivation (such as is brought 

 about by transferring spermatozoa to sea water without high 

 hydrogen ion or carbon dioxide concentration) which the experi- 

 mental conditions afford. The sooner spermatozoa become 

 inactive and the more completely inactive they become, the 

 longer their life. The hydrogen ion concentration of egg water 

 that is most effective in preserving the life of spermatozoa is 

 precisely that of acidified sea water that best subserves the same 

 function. 



Other effects of egg water upon the physiological condition of 

 spermatozoa have not been considered in this investigation. 



LITERATURE. 

 Buller, A. H. 



'oo The Fertilization Process in Echinoidea. Report of British Assoc. 70th 



Meeting, pp. 387-388. 



'02 Is Chemotaxis a Factor in the Fertilization of the Eggs of Animals ? Quar- 

 terly Journal Microscopical Science, Vol. 46, N. S., No. 181, pp. 145-176. 

 Child, C. M. 



'15 Senescence and Rejuvenescence, Chicago. 

 Cohn, E. J. 



'17 The Relation between the Hydrogen Ion Concentration of Sperm Suspen- 

 sions and their Fertilizing Power. Anatomical Record, Vol. u, No. 6, 

 P- 530. 

 Dewitz, J. 

 '85 Ueber die Vereinigung der Spermatozoen mit dem Ei. Archiv fiir die 



gesammte Physiologie, Bd. 37, pp. 219-223. 



'86 Ueber Gesetzmassigkeit in der Ortsveranderung der Spermatozoen und in 

 der Vereinigung derselben mit dem Ei. I. Archiv. fiir die gesammte 

 Physiologie, Bd. 38, pp. 358-385- 

 Drzewina, Anna, and Bohn, Georges. 



'12 Effets de 1'inhibition des oxydations sur les spermatozoides d'oursin et, 

 par leur intermediare sur le developpement. Comptes rendus des Seances 

 de 1'Academie des Sciences, Vol. 154, pp. 1639-1641. 

 Dungay, Neil S. 



'13 A Study of the Effects of Injury upon the Fertilizing Power of Sperm. 

 BIOL. BULL., Vol. 25, No. 4, pp. 213-256. 



