STRUCTURE OF DOMESTICATED AKIMALS. 295 



of yolk which is suspendecr in the egg by two cords of some- 

 what harder albumen than that which suiToiinds the yolk. 

 These two cords keep the yolk so suspended in the egg that' 

 whatever position you give the egg, certain parts always 

 remain uppermost. You may open any number of eggs and 

 you will always find that a little white speck stares you in 

 the face. You may turn the egg as you please, but that lit- 

 tle speck will always be uppermost. This is owing to the fact 

 that the yolk is heavier in one portion and lighter in another 

 and that it may swing upon the two strings of albumen by 

 which it is suspended. This speck, called blastoderm by em- 

 bryologists, is the part from which the young chick is devel- 

 oped when the egg is brought under proper conditions of 

 temperature, &c. 



As to the albumen, or white, it is not one mass ; it con- 

 sists of a number of la3'"ers ; and when you boil an egg so 

 that the whole is hardened, it is easy to see that it peels off in 

 these layers, which are deposited one after another. Now 

 such an egg has a history. It does not begin to be an egg of 

 that size ; it does not begin with having a shell ; it does not 

 begin with having these membranes within the shell ; it does 

 not begin with having the white around the yolk. There is 

 a time when the egg has neither shell, nor these membranes, 

 nor the white, but when the whole egg is yolk ; and you may 

 find such eggs in the organ called the ovary, in which the 

 eggs are produced. If we look carefully at the ovary of the 

 hen, we find that it contains a variety of eggs. It has eggs 

 which have attained to their full size — they are about the size 

 of a small walnut — it may contain a certain number of these — 

 but by the side of these large yolks there are smaller yolks 

 of various dimensions, and if you will examine minutely, you 

 will soon see that there are those, which, at the distance you are 

 from me, you could not see at all, even if I represented them 

 magnified a^ great many times ; and you gradually, by learning 

 to watch more and more closely, detect among this mass of eggs 

 which are readily visible, others which are less and less dis- 

 tinct to the eye ; and if you take a magnifying glass, you find 

 that there are others which had escaped your eye when you 

 had no magnifying power to help you ; and, if you use higher 

 and higher power, you begin to find that there are more and 



