OF REPRODUCTION. 97 



liquor called seed, prolific matter or seminal fluid i when this 

 liquid escapes from the urethra, it is composed of a substance se- 

 creted by the testicles, of the fluid exhaled from the vesiculae semi- 

 nales, and of the prostatic liquor. But which of all these various 

 elements is the fecundating principle? It is not the aura seminalis; 

 for Spallanzani could never fecundate the eg^s of frogs without 

 bringing them into immediate contact with the seminal liquor of the 

 male. Does it result from the mixture that I have just mentioned? 

 No; for the fluids furnished by the vesiculae seminales, the prostate 

 and the urethra, can only be regarded as the vehicle of that derived 

 from the testicles. Does it depend upon the animalcules named after 

 Lewenhoeck? Several authors maintain the affirmative, and their 

 opinion has found numerous echoes in various parts of the learned 

 world. 



243. According to Lewenhoeck, the animalcules are microscopic 

 corpuscles, endowed with the faculty of moving in a determinate di- 

 rection, and for a determinate end. Their large extremity, which 

 is also flattened, gives origin to their caudiform portion, which is 

 delicate and very much elongated. According to some of his parti- 

 sans, they may be divided into young, old, adult, weakly, strong, 

 male and female, Sic; and Plantade, of Montpellier, under the 

 assumed name of Dalempatius, refining still more on what had been 

 already advanced upon this subject, made out of a drop of prolific 

 liquor, a well governed nation; he imagined a king, princes, minis- 

 ters, magistrates, paupers, rich persons, merchants, soldiers, chil- 

 dren, old men, &c. Raillery produced, on this occasion, an eflect 

 that could not be brought about by the most peremptory reasoning. 

 The animalcular hypothesis appeared to be absurd, and thenceforth 

 nobody dared to advocate it. 



244. It is true that it had already been asserted that these corpus- 

 cles exist, and that they sometimes exhibit the form that had been 

 assigned to them, but that they also appear on some occasions un- 

 der another form, and that they do not in any case belong more 

 peculiarly to the seminal liquor than to any other of the animal 

 fluids; in a word, that they do not play any special part in the act 

 of reproduction, or at the least, they are not the essential agents of 

 fecundation. 



245. According to MM. Prevost and Dumas, the animalcules de- 

 scribed by Lewenhoeck do not exist except in the male organs of 

 generation, aijd diff'er from the mobile globules of the other fluids of 

 the organism by their form, which is always the same in the same 

 zoological species; by their mode of progression; by the situation in 

 which they are found, &c.; they always have an enlarged extremity 



