156 AMERICAN FISH CULTURE. 



transparent as the water itself; but if they turn milky, 

 and look like half-boiled sago, they are spoiled. 



" The contents are not, however, to be thrown away, 

 without taking up some in the hand, when it will likely 

 appear that but a small part are addled, while the rest re- 

 main transparent. With further progress the embryo may, 

 with a weak glass, be easily seen moving in the egg, which 

 then is not so clear, and at the end of sixty hours (with 

 sunshine and water at 75), the box will be found alive 

 with tiny fry, almost transparent, except the eyes, swim- 

 ming freely, with their heads up stream. In confinement 

 they cannot be kept, because the yolk-sac does not suffice 

 for their support for more than one or two days. But care 

 must be taken to liberate them in a safe place. Green 

 observed that, on setting them free among the shallows 

 near shore, the dace (Argyreus) and other little fishes 

 rushed to the spot, and commenced jumping at them. In 

 the stomach of a dace, he found fourteen shad fry. Then, 

 by a series of most ingenious experiments, he discovered 

 that the fry, so far from frequenting the shallows, like 

 many minnows, made directly for the main current, in mid- 

 river. How different this from the young trouts that lie 

 almost helpless for forty-five days, and then are fain to hide 

 behind stones and roots ! Whereas, these minute, trans- 

 parent, gelatinous things push boldly for the deep, swift 

 current, where they are too insignificant to be attacked by 

 the great fishes. Will the physicists tell us what ' corre- 

 lation and conservation of force' produces this, or will the 

 Darwinians set forth how, some millions of years gone, a 

 particular shad fry, finding by accident that he did not get 



