266 ON GENERATION. 



Hippocrates adds, 1 "Another indication or reason of the chick's 

 desiring to escape from the shell, is that when it wants food 

 it moves vigorously, in search of a larger supply, by which the 

 membrane around it is torn, and the mother breaking the shell 

 at the place where she hears the chick moving most lustily, 

 permits it to escape." 



All this is stated pleasantly and well by Fabricius ; but there 

 is nothing of solid reason in the tale. For I have found by 

 experience that it is the chick himself and not the hen that 

 breaks open the shell, and this fact is every way in conformity 

 with reason. For how else should the eggs that are hatched in 

 dunghills and ovens, as in Egypt and other countries, be broken 

 in due season, where there is no mother present to attend to 

 the voice of the supplicating chick, and to bring assistance to 

 the petitioner? And how again are the eggs of sea and land 

 tortoises, of fishes, silkworms, serpents, and even ostriches to 

 be chipped ? The embryos in these have either no voice with 

 which they can notify their desire for deliverance, or the eggs 

 are buried in the sand or slime where no chirping or noise 

 could be heard. The chick therefore is born spontaneously, 

 and makes its escape from the eggshell through its own efforts. 

 That this is the case appears from unquestionable arguments : 

 when the shell is first chipped, the opening is much smaller 

 than accords with the beak of the mother ; but it corresponds 

 exactly to the size of the bill of the chick, and you may always 

 see the shell chipped at the same distance from the extremity 

 of the egg, and the broken pieces, especially those that yield to 

 the first blows, projecting regularly outwards in the form of a 

 circlet. But as any one on looking at a broken pane of glass 

 can readily determine whether the force came from without or 

 from within, by the direction of the fragments that still adhere, 

 so in the chipped egg it is easy to perceive, by the projection 

 of the pieces around the entire circlet, that the breaking force 

 comes from within. And I myself and many others with me 

 besides, hearing the chick scraping against the shell with its 

 feet, have actually seen it perforate this part with its beak, and 

 extend the fracture in a circle like a coronet. I have further 



1 In lib. de nat. pueri. 



