34 OUR HUMBLE HELPERS 



your small powers of comprehension, I abridge, 

 much to my regret. 



"The yolk or yelk (which means the yellow part) 

 is round and bright yellow; hence its name. At a 

 point on its surface, generally at the top, no mat- 

 ter what the position of the egg, is seen a circular 

 spot, dull white, where the matter is a little more con- 

 densed than elsewhere. It is called the cicatricle, or 

 little scar. That is. the sacred spot where lies the 

 spark of life which, animated by incubation, will 

 quicken the substance of the egg and mold it into a 

 living being ; it is the point of departure, the origin, 

 the germ of the bird. The yolk itself is the nutritive 

 reservoir whence are drawn the materials for this 

 work of creation. Quickened by the heat of the 

 brooding hen and by the action of the air, it becomes 

 covered with a network of fine veins. These swell 

 with the substance of the yolk, which turns to blood ; 

 and this blood, carried hither and thither, becomes 

 the flesh of the being in process of formation. The 

 yolk, then, is the bird's first food, but food that no 

 beak seizes and no stomach digests, none being in 

 existence yet. It changes to blood and afterward 

 to flesh without the preparatory work of ordinary di- 

 gestion; it enters the veins directly, and thus nour- 

 ishes the whole body. 



"Animals with udders the mammifers also 

 have nutriment for the very young in the form of 

 milk, which is indispensable for the weak stomach of 

 the nursling. Well, the yolk is to the bird in its shell 

 what milk is to the lamb and kitten; it is its milk- 



