AND PREGNANCY. 367 



Verheyen, Hartman, and Duverney, could find no change in the 

 state of the tubes at any time, although their negative observa- 

 tions are completely overthrown by the positive observations of all 

 others who have enquired experimentally into the subject. Besides, 

 the great abundance of blood in the genital organs, during the sex- 

 ual ardour, must cause the tubes to enlarge and apply themselves 

 to the ovaria : this, as Haller mentions upon the authority of Hart - 

 soeker, occurs even in the dead body by means of injection. 



Dr. Haighton, however, to prevent the semen from passing along 

 the tubes, divided one of them in virgin rabbits, and, after the wound 

 was healed, admitted the animal to the male. The ovarium on this 

 side contained corpora hitea equally with the other, proving that 

 the Graafian vesicles had burst, although the semen could not pos- 

 sibly have reached the ovarium. * No foetus, notwithstanding, was 

 discoverable in any instance : on the other side (for in the rabbit 

 the uterus is double) foetuses were found equal in number to the 

 corpora lutea. Dr. Haighton concludes that impregnation may 

 take place without the advance of semen along the tubes. And 

 his conclusion is perfectly just, according to his test of impreg- 

 nation, the escape of the contents of a Graafian vesicle. But I 

 apprehend this to be no more deserving the title of a test of 

 impregnation than the emission of the semen masculinum. 

 Impregnation is that change wrought by means of the male 

 semen in the contents of a Graafian vesicle, which enables them 

 to become a foetus. Now this was never effected when the tube 

 was divided : although the presence of corpora lutea proved 

 vesicles to have burst, yet a foetus was in no one instance dis- 

 covered : in other words, the contents of the Graafian vesicles 



* The divided end of the tube was found totally impervious. The experi- 

 ment succeeded when one tube only was divided : the division of both deprived 

 the animal not only of fertility but of sexual desire, and even the division of 

 one had this effect in some instances. If the tube was divided after coition, the 

 result was the same, provided the operation was performed before the contents 

 of the vesicles had entered it ; for, if too much time had elapsed, the ova were 

 u-ansmitted to the uterus and ^rew to maturity. 



