ABSTRACT
A technique is described for the investigation of in vitro problems with spermatozoa removed from the vas deferens of the rabbit. The method involves the protection of the spermatozoa by means of liquid paraffin from evaporation or rapid gaseous exchange.
The survival of functional integrity (fertilising capacity) has been shown to be a function of temperature and the effect of temperature has been studied over the range from 45° C. to 0° C. Above body temperature the spermatozoa are rapidly destroyed. At body temperature (40° C.) maximal survival is about 13 hours. As the temperature is lowered survival becomes increasingly prolonged until a maximum of 7 days is reached at 15° C. The curve over the range from 15° C. to 40° C. is only approximately exponential and it is doubtful whether an analogy can be drawn between the effect of temperature on the velocity with which the spermatozoa are destroyed, and the effect of temperature on the velocity of many biological reactions which follow approximately the van’t Hoff and Arrhenius equations. Below the optimum temperature (10°-15° C.) the velocity of destruction is accelerated by fall of temperature.
The sex-ratio of the resulting offspring is not significantly altered by keeping the spermatozoa outside the body.
Sperm. This word is used throughout to denote the undiluted suspension of spermatozoa from the vas deferens.
The problem of this permanent sterility will be discussed in the companion paper by Ham-mond. In the present experiments cases were few and practically ceased after rigid precautions were taken to avoid transference of infective material from the vagina of one doe to another.
