366 OF CONCEPTION 



coition.* The peristaltic action of the tubes and their adhesion 

 to the ovaria during the venereal ardour, argue strongly in favour 

 of the semen being conveyed along them, because we can hardly 

 suppose these circumstances to begin to occur at tliis period for 

 the purpose of conveying the contents of the Graafian vesicle, 

 as this does not burst till a considerable time after copulation. 

 Dr. Haighton, indeed, says that these changes in the tubes 

 did not take place in his experiments till long (forty-eight hours) 

 after copulation, — till the ovaria were about to discharge into 

 them their vesicular fluids. In this he agrees with Bartholin, 

 De Graaf, Schurig, Deswig, and Lang, who maintained, like 

 him, that the semen, at least as far as examination went, does 

 not enter the lubes. f But Mr. Cruikshank and Mr. Saumarez, 

 two of the latest experimenters, assert the contrary in the detail 

 of their experiments, and, as Haller remarks of the old parti- 

 sans, the negative experiments of the former cannot overturn 

 the positive testimony of the latter, — " Eorum experimenta 

 negativa non possunt affirmantium fidem evertere :" Sbaragli, 



The well known instances of conception, where the admission of the male 

 organ into the vagina was prevented by the great strength of the hymen, are 

 sometimes cited against the opinion that the semen passes beyond the vagina, 

 but certainly with no weight. 1. Because the most minute portion of semen 

 is sufficient to impregnate : — Spallanzani mixed three grains of frog's semen 

 with a pound and a half of water, and with this fecundated nearly all the 

 numerous posterity contained in the threads taken from the female ; and, after 

 mixing three grains with even twenty-two pounds of water, he fecundated some. 

 (Dissertations, vol. 2. p. 191. English transl.) 2. Because the vagina lias 

 an action of its own sufficient to move the semen onwards to the uterus : — it 

 is seen during the cestrum of brutes (and also the uterus in a lower degree) 

 to have a peristaltic movement, it often firmly embraces the human placenta, 

 and Dr. Hamilton, the present obstetric professor of Edinburgh, mentions, 

 in his lectures, having attended a physometric patient whose vagina sucked 

 up air from without, as appeared from the emission of air ceasing in the warm 

 bath; Dr. Monro sccundus likewise was perfectly satisfied that the woman 

 drew in the air. 



* Experimental enquiry, &c. by John Haighton, M.D. Philos. Trans. 1797. 



t Haller, Elem. Physiol, and notes to Boerhaave, 1. c. 



