ARTIFICIAL HATCHING OF SPAWN. 45 



example, settled over the gravel, would, perhaps, 

 though not absolutely to a certainty, consign the ova 

 to destruction. Ova may be, and often is, hatched in 

 the damp moss, while being conveyed from place 

 to place, if the eggs chance to be very forward ; 

 but, unless the fry is removed to water, it will 

 scarcely survive its exit from the shell any length 

 of time. I have elsewhere said, that I could hatch 

 salmon with a tumbler of water and a cheese plate, 

 and this is no exaggeration ; nor, provided the 

 water were kept moderately cool, and changed 

 occasionally, would there be the least difficulty 

 in it, a running stream being by no means indis- 

 pensable. What current can there be in the natural 

 condition when the eggs are three or four inches 

 under the gravel? Still, the water must not be 

 allowed to become stagnant, as putrefaction begets 

 putrefaction, and in nothing more quickly than fish 

 ova. When one egg goes bad, it turns white and 

 opaque ; putrefaction soon sets in ; a peculiar starry 

 fungoid growth radiates from it, and finally becomes 

 much of the consistence and appearance of hair, or 

 rather hemp. Soon after, this touches the next egg, 

 it adheres to it, and that egg in time turns off also. 

 It is useless to attempt to clear eggs to which this 

 substance has adhered ; indeed, much harm may 



