1 88 



EDWIN J. COHX. 



formed with the ions of sea water be toxic to the organism under 

 investigation. According to a personal communication, C. M. 

 Child has observed distinct toxic action of the concentrations of 

 borates used in these experiments upon developing sea urchin 

 eggs. It is therefore possible that the action of borates in short- 

 ening the life of the sperm is in part due to their toxicity. 



TABLE VII. 



THE RELATION BETWEEN THE LENGTH OF LIFE OF A CONCENTRATED SPERM SUS- 

 PENSION AND THE RATE AT WHICH THE CARBON DIOXIDE PRODUCED 

 BY SPERMATOZOA is NEUTRALIZED BY ISOHYDRIC BORATES. 



Experiment 208. 



Experiment 205. 



Experiment 223. 



1 The eggs of a female that had been opened at 1.30 P.M. were used in this 

 series of inseminations. They were evidently more easily fertilized than the eggs 

 <>t the female that had been opened at 9.30 A.M. 



