THE HISTORY OF FISH-CULTURE. 529 



Hatclihuj from the oj^al of dead fshcs. — There exists quite a prevalent 

 uotiou tbat the stock of iishes may be protected from dimiiiatiou to a 

 considerable extent by returning the offal from fishes dressed for salt- 

 ing, containing the ov'aries and spermaries, to the waters from whence 

 the fishes are taken. This is done to a large extent at Sandusky, Ohio, 

 on Lake Erie, where the white-fish {Corcgonns albus) is taken in large 

 numbers in the spawning-season, and the fishing-grounds are so far 

 off from the curing-houses that but little damage is done by the presence 

 of the decaying matter. 



That the ova from fishes dead for a short period of time may be fertil- 

 ized and hatched has been proven by experiment by embryologists and 

 fishculturists. 



Jacobi, in his early experiments, found that young fishes could be 

 developed from the eggs and milt of fishes recently dead. 



M. de Quatrefages, in referring to the fertilization of fishes, says the 

 fecundation should follow soon upon the death of the male fish, and 

 the second clause of his directions says, " Since the fecundation should 

 take place within a day or twelve hours after the death of the fish, 

 the spawn should then be taken." 



In Carl Vogt's essay on artificial fish-breeding he says, in speaking of 

 the fertilizing power of the spermatozoa : " At low temperatures this 

 power is retained for hours and even days if the milt remains in the 

 organs by which it is secreted. In the Lake of Keufchatel (Switzerland) 

 the palee, {Coregonus palea,) a fish of the trout family, is taken, during 

 the winter months, b}^ night or at sunset. I have often received these 

 fish stiff-frozen, and succeeded perfectly in impregnating spawn with 

 the milt taken from the genitals of the male the day after." 



On page 497 of this report is a reference to the success the Eussian 

 fish-culturists have had in hatching the eggs from dead females impreg- 

 nated with the milt from dead males, the claim being made that the 

 milt retains its vitality for a long time if left within the reproductive 

 organs. 



Mr. Atkins (see pp. 285-86) gives the percentage of eggs fecundated 

 taken from dead females, as follows : From a salmon that had been dead 

 two hours, at .58^ ; of eggs from two dead females, at .67i ; of eggs from 

 two dead females, at .35; of eggs from dead fish, .92^; of eggs from 

 dead fish, .30; of eggs taken from dead fish the day before, .12i ; of eggs 

 taken on I^Tovember 11 from specimens killed on the 9th, .0 ; from a 

 fish that had been dead fifteen hours, .0. The experiments with eggs 

 from live females, to which the milt from dead males was applied, ^ave 

 the following results : Female ripe and good, milt, about a teaspoonful, 

 from a dead fish taken before the eggs, .2J ; eggs kept in a pan without 

 water thirty hours, milt from a male that had been dead two days, .0 ; 

 from eggs kept the same length of time, treated with fresh milt, .87^; 

 eggs kept without water four days, milted with milt from dead fish, .0; 

 eggs kept four days without water, then milted with new milt, .12J. 

 S. Mis. 74 34 



