J. PISCICULTURE AND THE FISHERIES. 405 



duction on the part of the fish themselves, or to protective 

 measures, however stringent, for the future supply. 



Another state equally interested in the object in view with 

 Michigan and Canada is Ohio, and her Commissioners have 

 also been doing what circumstances would permit them in 

 the same direction. They have established four hatching- 

 houses one at Cleveland, in connection with the water- 

 works; one at Castalia Springs, near Sandusky; one at Tole- 

 do, in connection with the water-works; and one on Kelly's 

 Island, in Lake Erie. So much time was occupied in getting 

 these stations ready that the Commissioners could not pro- 

 cure a large stock of eggs, but expect to do their full share 

 another season. In this emergency the Michigan Commis- 

 sioners generously presented them with 800,000 whitefish 

 eggs, which have been distributed to the diiferent establish- 

 ments to be hatched out. 



ONE CAUSE OF DEATH OF FISHES. 



In inquiring into the cause of the death of many fishes, 

 M. De la Blanchere considers this largely connected with the 

 exhaustion caused during reproduction, and calls attention 

 to well-known facts in the history of large trout under such 

 circumstances. 19 j5, June 10, 188. 



RAPIDITY OF GROWTH IX CERTAIN FISHES. 



Mr. Mitchell, in a communication to Nature^ presents some 

 remarkable facts in regard to the rapidity of growth of fishes. 

 Referring to a species of carp, called by the natives Katlah^ 

 he states that this is a species that does not breed in fresh 

 water, but that the natives are in the habit of introducing 

 the fry into ponds, etc., where they thrive very satisfactorily. 

 According to his account, a tank sixty-five feet long, fifty- 

 eight feet broad, and thirteen feet deep was dug within the 

 premises at Garden Reach, in May, 1875, and a number of the 

 Katlah fry, from half an inch to an inch in length, were in- 

 troduced about the end of July. On the 22d of September 

 the tank was swept with nets to catch one or two fish of the 

 pike species that had been accidentally introduced with the 

 others. In the net were taken several dozens of the carp re- 

 ferred to, one of Avhich weighed fourteen ounces, and was 

 eleven inches in length. Others were only a few ounces 



