The Effect of Temperature on the Survival In Vitro of Rabbit Spermatozoa Obtained from the Vagina

Abstract

1. The time during which spermatozoa, obtained from the vagina of the female rabbit after service, retain their fertilising power when kept in vitro at diferent temperatures has been determined. 2. At 35° C., or just below body temperature, young are obtained up to 14 hours at 10° C. up to 96 hours and at 0° C. up to 16 hours, there being a well-marked optimum temperature for survival. 3. Not only does the percentage of animals fertile fall with increase in the length of time the semen is kept, but also the average size of the litter decreases in the small litters so obtained the birth weight is increased considerably and the duration of pregnancy slightly lengthened. 4. The percentage of spermatozoa motile, when examined at room temperature is a fairly good indication of the percentage fertility. 5. The sex-ratio is not materially affected by keeping the sperm. 6. Sterility due to adherent tubes was frequent during the course of the experiments. 7. These results with semen obtained from the vagina are compared with those obtained in a parallel series direct from the epididymis of the male under paraffin