ON GENERATION. 331 



a fact which Aldrovandus was either ignorant of or concealed. 

 Fabricius admits this fact ; but though he has denied that the 

 semen of the male penetrates to the uterus or is ever found in 

 the egg, he nevertheless, contends, that the chalazse alone of 

 all the parts of the egg are impregnated with the prolific 

 power of the egg, and are the repositories of the fecundating 

 influence ; and this, with the fact staring him in the face all 

 the while, that there is no perceptible difference between the 

 chalazse of a prolific and an unprolific egg. And when he admits, 

 that the mere rudiments of eggs in the ovary, as well as the 

 vitelli that are surrounded with albumen, become fecundated 

 through the intercourse of the cock, I conceive that this must 

 have been the cause of the error committed by so distinguished 

 an individual. It was the current opinion, as I have said 

 oftener than once, both among philosophers and physicians, 

 that the matter of the embryo in animal generation, was 

 the geniture, either of the male, or of the female, or resulted 

 from a mixture of the two, and that from this, deposited in 

 the uterus, like a seed in the ground, which produces a plant, 

 the animal was engendered. Aristotle, himself, is not very far 

 from the same view, when he maintains the menstrual blood 

 of the female to be the seed, which the semen of the male 

 coagulates, and so composes the conception. 



The error which we have announced, having been admitted 

 by all in former times, as a matter of certainty, it it not to be 

 wondered at, that various erroneous opinions based on each 

 man's conjecture, should have emanated from it. They, how- 

 ever, are wholly mistaken, who fancy that anything in the 

 shape of a ' prepared or fit matter ' must necessarily remain 

 in the uterus after intercourse, from which the foetus is pro- 

 duced, or the first conception is formed, or that anything is 

 immediately fashioned in the uterine cavity that corresponds 

 to the seed of a plant deposited in the bosom of the ground. 

 For it is quite certain, that in the uterus of the fowl, and the 

 same thing is true of the uterus of every other female animal, 

 there is nothing discoverable after intercourse more than there 

 was before it. 



It appears, consequently, that Fabricius erred when he 

 said : * "In the same way as a viviparous animal is incorpo- 



1 Op. sup. cit. p. 35. 



