216 ON GENERATION. 



EXERCISE THE THIRTEENTH. 



Of the diversities of eggs. 



" The word ovum, or egg, is taken in a twofold sense, proper 

 and improper. An ovum, properly so designated, I call that 

 body to which the definition given by Aristotle 1 applies : An 

 egg, says he, is that from part of which an animal is engen- 

 dered, and the remainder of which is food for the animal so 

 produced. But I hold that body to be improperly styled an 

 egg which is defined by Aristotle 2 in the same place, to be that 

 from the whole of which an animal is engendered; such as the 

 eggs of ants, flies, spiders, some butterflies, and others of the 

 tribe of extremely small eggs ; which Aristotle almost always 

 fears to commit himself by calling eggs, but which he rather 

 styles vermiculi." What precedes is from Fabricius; 3 but we, 

 whose purpose it is to treat especially of the generation of the 

 hen's egg, have no intention to speak of the differences of all 

 kinds of eggs ; we shall limit ourselves to the diversities among 

 hen's eggs. 



The more recently laid are whiter than the staler, because 

 by age, and especially by incubation, they become darker ; the 

 cavity in the blunt end of a stale egg is also larger than in a 

 recent egg ; eggs just laid are also somewhat rough to the feel 

 from a quantity of white powder which covers the shell, but 

 which is soon rubbed off", when the egg becomes smoother as 

 well as darker. New-laid eggs, unbroken, if placed near a fire 

 will sweat, and are much more palatable than those that have 

 been kept for some time they are, indeed, accounted a delicacy 

 by some. [Fruitful] eggs, after two or three days' incubation, 

 are still better flavoured than stale eggs ; revived by the gentle 

 warmth of the hen, they seem to return to the quality and 

 entireness of the egg just laid. Farther, I have boiled an egg 

 to hardness, after the fourteenth day of incubation, when the 

 chick had already begun to get its feathers, when it occupied 

 the middle of the egg, and nearly the whole of the yelk re- 



1 Hist. Anim. lib. i, cap. 5. * Ibid. cap. 2. 3 Op. cit. p. 19. 



