EFFECT OF pH ON THE SWIMMING RATE OF BULL SPERMATOZOA

Summary. Measurements were made of the swimming rate of bull spermatozoa at a concentration of 10,000 cells per μl in physiological saline solution and in saline solution buffered with 0·014 m-phosphate at pH values of 6·5, 7·5 and 8·5. The buffers at pH 6·5 and 7·5 gave results similar to those for unbuffered saline solution. At pH 8·5 there was an initial advantage, both in percentage motile and in swimming rate. By the end of 1 hr, the spermatozoa were, however, swimming more slowly, and fewer were surviving than in any other medium. The significance of these results in relation to the swimming of spermatozoa in the female tract is discussed.