3.56 ON GENERATION. 



Neither is there anything contained in the uterus imme- 

 diately after intercourse, which, proceeding from the male, or 

 from the female, or from both, can be regarded as the matter 

 or rudiment of the future foetus. Neither is the semen galli 

 stored and retained in the bursa Fabricii of the hen or else- 

 where, that from thence, as by the irradiation of some spiri- 

 tual substance, or by contact, the egg may be fashioned or 

 the chick constituted from the egg. Neither has the hen 

 any other semen save papules, yelks, and eggs. These obser- 

 vations of ours, therefore, render the subject of generation 

 one of greater difficulty than ever, inasmuch as all the pre- 

 sumptions upon which the two old opinions repose are totally 

 overthrown. The fact is especial, as we shall afterwards 

 demonstrate, that all animals are alike engendered from eggs ; 

 and in the act of intercourse, whether of man or the lower 

 quadrupeds, there is no seminal fluid, proceeding from the 

 male or the female, thrown into the uterus or attracted by 

 this organ ; there is nothing to be discovered within its cavity, 

 either before intercourse, during the act, or immediately after 

 it, which can be regarded as the matter of the future foetus, 

 or as its efficient cause, or as its commencement. 



Daniel Sennert, a man of learning and a close observer of 

 nature, having first passed the reasonings of a host of others 

 under review, approaches the subject himself; and concludes 

 that the vital principle inheres in the semen and is almost 

 identical with that which resides in the future offspring. So 

 that Sennert does not hesitate to aver that the rational soul 

 of man is present in his seminal fluid, and by a parity of 

 reasoning that the egg possesses the animating principle of the 

 pullet ; that the vital principle is transported to the uterus of 

 the female with the semen of the male, and that from the 

 seminal fluids of either conjoined, not mixed (for mixture, he 

 says, is applied to things of different species), and endowed 

 with soul or the vital principle a perfect animal emerges. And 

 therefore, he says, the semen of either parent is required, 

 whether to the constitution of the ovum or of the embryo. 

 And having said so much, he seems to think that he has over- 

 come all difficulties, and has delivered a certain and perspicuous 

 truth. 



But in order that we should concede a soul or vital principle 



