330 OP TIIK GENITAL FUNCTION IN MAN. 



Their strength of constitution being an important object of en- 

 quiry, they gave proofs of their vigour not only by surviving 

 their rough passage through the urethra, three, four, and seven 

 days, but by impregnating a female at the end of this time, and, 

 on being removed from her, by impregnating even a second. 

 Sure never was so much folly and bestiality before committed 

 under the name of philosophy. 



Abr. Kauw Boerhaave, Maupertuis, Lieutaud, Ledermuller, 

 Monro Secundus, Nicolas, Haller, and indeed nearly all the phi- 

 losophers of Europe, were satisfied of the existence of the animal- 

 cules. Buffon and his followers, prejudiced in favour of an hypo- 

 thesis, although they did not deny that the semen contained 

 innumerable rapidly moving particles, contended that these 

 were not animalcules but organic particles, and Liniueus imagined 

 them to be inert molecules thrown into agitation by the warmth 

 of the fluid. Their reality, however, might be regarded as esta- 

 blished. But finally to determine the question, and accurately 

 to ascertain every circumstance relating to them, the celebrated 

 Spallanzani began a long course of observations and experiments 

 about the middle of the last century, unbiassed in favour of any 

 opinion, and endeavouring to forget entirely all that had been 

 written upon the subject. The human semen he procured from 

 bodies immediately after death, and that of animals either after 

 death or during life. 



He found in the former, innumerable animalcules with an 

 oval body and a tail or appendix tapering to a point. This ap- 

 pendix by moving from side to side propelled them forwards. 

 They were in constant motion in every direction. In about 

 twenty-three minutes their movements became more languid, 

 and in two or three hours they generally died, sinking to the 

 bottom of the fluid, with their appendices extended. The dura- 

 tion of their life, however, depended much upon the tempera- 

 ture of the weather ; at 2 below O (Reaumur) they died in | of 

 an hour ; while at 7° they lived 2 hours ; and at 12$, 3 hours 

 and three quarters. If the cold was not too intense, they 

 recovered upon the temi>erature being raised ; when only 3 or 



