476 AMERICAN ANGLER'S BOOK. 



which covers about a quarter of its circumference. This line, 

 which seems whitish when the eggs are on a dark ground, or 

 opaque when they are held up to the light (in the manner in 

 which our farmers examine hens' eggs), is the origin of the 

 foetus, and represents the spinal column. As this line in- 

 creases in size, one end of it grows out to a point to form a 

 tail, and the other extends in the form of a spatula. This 

 last corresponds to the embryo's head, and of this there is 

 soon no doubt, for the eyes now appear, two points of a 

 blackish brown, easily distinguished, and forming nearly 

 two-thirds of the whole mass of the head. As each day 

 develops its form, the young fish may be seen under the 

 shell or membrane, stretching itself, and drawing itself up, 

 and wagging its tail. When hatching-time comes, these 

 movements, the probable object of which is to weaken or tear 

 the shell, become more active. With Salmon and Trout 

 there is another sign of the approach of hatching besides the 

 quick movements of the young. The out^r envelope of the 

 egg becomes a little opaque, and as it were furfuraceous. 

 With other species with which I have made observations, 

 this sign does not appear so plainly. At last a little opening 

 is made in the shell, and that part of the embryo next the 

 opening comes through it. Ordinarily the tail or the head 

 first appears, but sometimes it is the umbilical bladder. 



•'' Whatever part may be first disengaged, more than half 

 the body still remains imprisoned, and the efforts of the 

 young fish are unceasing, till after several hours it frees 

 itself from the shell. This membrane, which has protected 

 its development, hut has not served to form any part of its 

 organs, being now cast off* either is decomposed where it lies, 

 or is carried off by the current. 



" Certain kinds, like the Pike and the Ferrat, begin imme- 

 diately to range about in the waters where they have just 



