iv THE GENEKATIVE SYSTEM OF THE MALE 127 



well with an observation by Bischoff, who found spermatozoa 

 in the ovary of a rabbit 9 or 10 hours after coitus. It is in 

 virtue of their active locomotion that the spermatozoa are able to 

 reach the ovum in order to fertilise it, ascending along the uterine 

 tubes after overcoming the pressure exerted in the opposite direction 

 by the ciliary movement of the tubal epithelium. 



The spermatozoa exhibit a positive chemotaxis to the mucus of 

 the cervix of the uterus, as one may indeed ascertain in microscopic 

 preparations (Chrobak). They show, on the otber hand, a negative 

 chemotaxis in regard to the acid mucus of the vagina (Seligmann). 



The most important researches on this question are those of 

 O. Lows (1902), who has clearly demonstrated the chemotatic 

 action of the uterine and tubal mucus, which is greater than that 

 of a simple alkaline solution of equal concentration. 



The vitality of the spermatozoa is very great. Under suitable 

 conditions they can continue to live for several weeks even outside 

 the male organ from which they arose. Ahlfeld has seen them 

 alive and moving after having been kept in an incubator for eight 

 days ; HausmRnn has found them alive in the female genitals a 

 week after coitus, Diihrssen after three weeks and a half. 



By the addition of water to the semen the movements of the 

 spermatozoa are arrested more or less rapidly according to the 

 degree of dilution ; but after being rendered immobile they can 

 become active again on the addition of saline solutions which bring 

 back the seminal fluid to the normal concentration. Even acid 

 solutions do not inhibit the movements. On the other hand, 

 weak alkaline solutions favour and increase their mobility and 

 may even restore it after it has ceased. In the same way act 

 solutions of sugar, urea, and some salts. Very strong alkaline 

 solutions and also strong solutions of neutral substances (such as 

 chloride of sodium, urea, sugar) inhibit the movements, and are 

 harmless only in certain concentrations. Spermatozoa, as other 

 cells of the body, are in a state of osmotic tension different from 

 that of the protozoa which live freely in water. 



Different temperatures also act on the vitality of spermatozoa. 

 The optimum for their mobility is 35 (Engelmann). The upper 

 limit is 43-44 for human semen (Mantegazza). Cooling retards 

 and suspends the movements, but they can be brought back to 

 their former state even after the semen has been maintained at 

 for six days (Mautegazza). The revivifying of the spermatozoa 

 is possible even after subjecting them to the intense cold of - 15. 



II. The sperm formed by the convoluted seminiferous tubules 

 collects in the straight tubules which pass through the spongy 

 spaces of the corpus Highmori, in the rete testis, the efferent 

 tubes, the canals of the lobules of the epididymis, and the vas 

 deferens (Fig. 22). 



The epididymis, like the testicle, is divided into lobules called 



