REPORT OF 



Ou December 8 



COMMISSIONER OP FISH AND FISHERIES. LXXV 



ix lots were examined, as follows : 



From tbese experiments it would seem that neither spawn nor milt 

 retain tbeir fertility after the third day; but this is not necessarily the 

 case, as the milt used in all of these long-time experiments, with one 

 exception, was from the lot of December 4, which had been repeatedly 

 uncorked and possibly injured by the admixture of a small amount 

 of water, while the spawn was held in small lots of a half pint or less, 

 which were more liable to dry out than a large mass. All of the eggs 

 used in this experiment, except one lot, were placed in a jar marked 

 "miscellaneous," and examined from time to time, showing a good per- 

 centage of impregnation. Before being placed in the jars they were 

 held separately in kegs for two or three days with running water and 

 reexamined to observe if the development seemed natural, and no dif- 

 ference could be seen between these and eggs of the same age taken 

 at the same time in the usual manner. It is a matter of regret that 

 there were not enough taken at one iime to fill a jar, so that they could 

 have been carried separately up to the hatching period. 



An experiment was also tried with a view to hatching whiteflsh eggs 

 with closed circulation — that is, using the water over and over. The 

 water was pumped into a 12-gallon keg, whence it descended by gravity 

 to the jar, thence to a large tin vessel, which was partially submerged 

 in running water in order to maintain a low temperature. From this 

 it was again pumped back to the keg. This experiment was continued 

 for 13 days without damage to the eggs, although, owing to the fact 

 that the temperature of the water was 7° warmer than that taken from 

 overboard, the development was much more rapid. It may also be 

 stated that so much oil was carried over from the pump that It formed 

 a considerable coating on the surface of the water in the receiving 

 vessel, also on the inside of the jar. The eggs, however, were apparently 

 not injuriously affected by this circumstance. These eggs hatched 

 before any others in the house, and the fry were apparently as healthy. 



Collections of eggs were made, as heretofore, from the commercial 

 fishermen, but owing to the unfavorable conditions prevailing during 

 November, the total collections amounted to only 112,842,000 whitefish 

 and 27,786,000 cisco or lake herring. From the nets fished in the 

 vicinity of Port Clinton, 40,653,000 whitefish eggs were obtained; from 



