ON GENERATION. 227 



the chick in ovo is perfectly correct. Nevertheless, as if he 

 had not himself seen the things he describes, but received them 

 at second hand from another expert observer, he does not give 

 the periods rightly ; and then he is grievously mistaken in re- 

 spect of the place in which the first rudiments of the egg are 

 fashioned, stating this to be the sharp end, for which he is fairly 

 challenged by Fabricius. Neither does he appear to have ob- 

 served the commencement of the chick in the egg; nor could 

 he have found the things which he says are necessary to all 

 generation in the place which he assigns them. He will, for 

 instance, have it that the white is the constituent matter (since 

 nothing naturally can by possibility be produced from nothing.) 

 And he did not sufficiently understand how the efficient cause 

 (the seminal fluid of the cock,) acted without contact ; nor how 

 the egg could, of its own accord, without any inherent generative 

 matter of the male, produce a chick. 



Aldrovandus, adopting an error akin to that of Aristotle, says 

 besides, that the yelk rises during the first days of the incubation 

 into the sharp end of the egg, a proposition which no eyes but 

 those of the blind would assent to; he thinks also that the cha- 

 lazse are the semen of the cock, and that the chick arises from 

 them, though it is nourished both by the yelk and the white. 

 In this he is obviously in opposition to Aristotle, who held that 

 the chalazse contributed nothing to the reproductive powers of 

 the egg. 



Volcherus Goiter is, on the whole, much more correct; and his 

 statements are far more consonant with what the eye perceives. 

 But his tale of the three globules is a fable. Neither did he 

 rightly perceive the true commencement of the chick in ovo. 



Hieronymus Fabricius contends that the chalazae are not the 

 sperma of the cock; but then he will have it that "from these, 

 fecundated by the seminal fluid of the cock, as from the appro- 

 priate matter, the chick is incorporated." Fabricius observed 

 the point of origin of the chick, the spot or cicatricula, namely, 

 which presents itself upon the tunica propria of the yelk ; but he 

 regarded it as a cicatrice or scar left on the place where the 

 peduncle had been attached ; he viewed it as a blemish in the 

 egg, not as any important part. 



Paiisanus completely refutes Fabricius's ideas of the cha- 

 lazse ; but he himself obviously raves when he speaks of certain 



