ON 



ANIMAL GENERATION. 



EXERCISE THE FIRST. 



Wherefore we begin with the history of the hen's egg. 



Hieronymus Fabricius of Aquapendente, (whom, as I have 

 said, I have chosen my informant of the way I am to follow,) 

 in the beginning of his book on the Formation of the Ovum and 

 Chick, has these words : " My purpose is to treat of the forma- 

 tion of the foetus in every animal, setting out from that which 

 proceeds from the egg : for this ought to take precedence of 

 all discussion of the subject, both because from this it is not 

 difficult to make out Aristotle's views of the matter, and be- 

 cause his treatise on the Formation of the Foetus from the egg, 

 is by far the fullest, and the subject is by much the most ex- 

 tensive and difficult." 



We, however, commence with the history of the hen's egg 

 as well for the reasons above assigned, as because we can thence 

 obtain certain data which, as more familiar to us, will serve to 

 throw light on the generation of other animals ; for as eggs cost 

 little, and are always to be had, we have an opportunity from 

 them of observing the first clear and unquestionable commence- 

 ments of generation, how nature proceeds in the process, and 

 with what admirable foresight she governs every part of the 

 work. 



Fabricius proceeds : " Now that the contemplation of the 

 formation of the chick from the egg is of very ample scope, ap- 

 pears from this, that the greater number of animals are pro- 



