IONIC AND OSMOTIC CONDITIONS 79 



Table VI. Effect of bicarbonate level and of pH on the percentage of 

 motile spermatozoa after storage at 5°C in Na citrate-bicarbonate diluents 

 containing yolk saturated with C0 2 (mean of 1 1 replications)" 



VanDemark and Bartlett (1960). 



of the solution. The pH of a 0.025M solution of sodium bicarbonate, 

 first used in our studies, is about 6.2 when saturated with C0 2 gas. 

 This pH is not quite as low as that measured in the fluid of the cauda 

 epididymis of the bull by Bran ton (6.07 ± 0.13) (Branton, 1946), nor 

 is it low enough to produce maximum control of glycolysis as shown 

 in Table III, IV, or V, and Fig. 6. From these facts and such data as 

 are presented in Table VI we reason that the control of anaerobic 

 glycolysis is not due to the extracellular pH of the diluent. In Table 

 VI the diluent supporting maximum livability of the spermatozoa 

 contained 0.1 M sodium bicarbonate and was at a pH of 6.75 ini- 

 tially which increased to 6.98 after 60 days' storage. Both of these pH 

 levels would have supported maximum activity. We still know 

 nothing about the intracellular pH of the spermatozoa in the various 

 diluents and /;C0 2 , but the metabolic control by C0 2 does not result 

 solely from its effect on the pH of the media of sperm cell suspen- 

 sions. 



RELATION OF SULFUR TO SPERMATOZOAN METABOLISM 



As stated in the first part of this review, we have been unable to 

 stimulate the endogenous respiration of bull epididymal spermatozoa 

 by additions of sulfide, sulfite, or sulfur-containing organic com- 

 pounds as reported by Lardy (1953), but have found conditions which 

 remind us of some of the observations he and his co-workers made. 



