370 M. P. Tasclicr on the Fecundation 



day, apart from the days of rest, representing intervals of 

 40-44 lioiirs, wliich intervene with a certain regularity. With 

 regard to the second point my results are equally at variance 

 with those of M. Coste. The examination of more than 20 

 fresh ovaries, undertaken at times Avhen semen ought to be 

 found there if it ordinarily reaches the ovary, gave in most 

 cases a negative result ; only in two cases was living semen 

 found ; in three others some dead spermatozoa were observed. 

 Only once was a living spermatozoon found outside a mature 

 follicle, wdiicli was free from the infundibulum ; of four follicles 

 which were embraced by the infundibulum, three showed a few 

 spermatozoa. I have never found spermatozoa inside an entire 

 follicle. I therefore do not believe that the semen ascends to 

 the ovary otherwise than quite exceptionally. In order to 

 ascertain the time occupied by the semen in ascending through 

 the oviduct to the infundibulum, several hens which had been 

 kept by themselves for some time were paired, again isolated, 

 and killed from 10-24 hours after. In one case, after 10 hours, 

 a great quantity of living semen was found in the base of the 

 infundibulum, but very little either in the other part of the 

 duct or on the margin of the infundibulum ; in a second 

 instance the semen was found, 12 hours after pairing, in the 

 tipper part of the tube, but next to nothing in the infundibu- 

 lum ; in a third case, after 14 hours, much semen was found 

 in the upper part of the tube and a little in the base of the 

 infundibulum ; in a fourth hen, after the same interval, the 

 semen was found all over the infundibulum ; in a fifth instance, 

 after 15 hours, nearly all the semen had passed into the base of 

 the infundibulum, but some remained in the upper part of the 

 tube; in a sixth case, after 16 hours, semen was found all 

 over the infundibulum, though but little occurred near the 

 base ; none was found in the tube ; finally, in a hen which 

 had l3een kept isolated for 24 hours after pairing, semen was 

 found only along the margin of the infundibulum, in and 

 above the " pitted zone " to be described hereafter. This hen 

 had laid a sterile egg 23 hours after being paired, Avhicli con- 

 sequently must have encountered the ascending semen a few 

 hours before entering into the fourth division of the oviduct, 

 in which the shell is formed. It cannot be doubted that some 

 few spermatozoa remain in the duct; but it seems unquestion- 

 able that the semen ascends in bulk into the infundibulum ; 

 and my experiments show that it requires from 10-16 hours 

 in order to reach the infundibulum, and at least 14 hours to 

 reach the pitted zone. 



I have no hesitation in saying that if M. Coste had based 

 his experiments and arguments on the assumption of an in- 



