STUDIES IN THE PHYSIOLOGY OF SPERMATOZOA. 



Because of this property of carbonate solutions it is necessary 

 to know not only the hydrogen ion concentration but also the 

 carbon dioxide tension. The latter is, as stated, above expressed 

 by the number of millimeters of mercury that represents the 

 partial pressure of the gas. The procedure usually followed was 

 to restore the equilbrium between the sea water (of whatever 

 hydrogen ion concentration) and the carbon dioxide of the air, 

 before beginning an experiment. This was accomplished either 

 by shaking with air, or by bubbling air through the solutions. 



In a series of experiments it was found that the more alkaline 

 the solution (i. e., the lower the hydrogen ion concentration) the 

 shorter the life of the sperm. The activity of the spermatozoa 

 is increased in these suspensions, and spermatozoa that are 

 added to ripe eggs in sea water while in this activated condition 

 have a greater "fertilizing power" (this has been previously 

 reported. See Fuchs, H. M., 1915) than spermatozoa that have 

 been in less alkaline sea water. This lasts for a much shorter 

 time, since the life of spermatozoa is very short in alkaline solu- 

 tion. (If the hydrogen potential is greater than about Ph 9.4 

 spermatozoa are instantly agglutinated.) In order to demon- 

 strate the increased "fertilizing power" of spermatozoa that have 

 been in alkaline solution it is necessary to inseminate in such 

 dilution that the spermatozoa that have been in sea water with 

 greater hydrogen ion concentration do not fertilize all of the eggs. 



Experiment 227 illustrates both the effect of alkaline sea water 

 in increasing the "fertilizing power" for a short time and of more 

 acid sea water in increasing the time during which the "fertilizing 

 power" is exhibited. The reversal in the effect of alkaline sea 

 water upon the "fertilizing power" of spermatozoa was demon- 

 strable only because the eggs used in the first part of this experi- 

 ment were fertilized with difficulty. Otherwise the early fer- 

 tilizations would have been complete, and the effect of alkaline 

 sea water upon spermatozoa not have been observed. Diagram 

 III. represents the prolongation of the life of the sperm in acid 

 suspension. The ordinates measure the fertilizing power of the 

 sperm at the times designated by the abscissae. The hydrogen 

 potentials of the suspensions are symbolically recorded. 



If sea water is much more alkaline than Ph 9.4, spermatozoa 



