258 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



5.— THE SUSCEPTIBILITY OF THE EGGS TO FECUNDATION IN WATEE. 



Experiment 2, Octoher 29.— Lot 34 treated in the usual way; fecunda- 

 tion 100 per cent. Lot 36, from same female, allowed to stand in water 

 two minutes, before the milt was applied, which was done without 

 pouring off the water ; fecundation 20 per cent. Water, 44° F. 



Experiment 3, Octoher 31.— Lot 40 treated with water four miuutes 

 before the application of milt; fecundation 7^ per cent. Water, 43° F. 



Experiment 4, November 4.— Temperature of the water 40^ F. Lot 

 119, treated as usual, was completely fecundated. Lot 120, from the 

 same fish, stood in water several miuutes before the milt was applied; 

 fe<!undation, none. 



Experiment 5, November 5.— Temi)erature of the water 40° F. Lots 

 136, 137, 138, 139 and 140. The milt for these eggs was taken first 

 in a dish, dry; then the eggs were taken, divided and watered; 

 then, after the lapse of one, two, three, and six minutes, respect- 

 ively, the milt was applied and the eggs stirred; all then stand 

 until free. Results : after one, two, and three minutes, fecundation 

 100 per cent; after four miuutes, 92J per cent; after six minutes, 

 65 per cent. 



Experiment 6, November 11.— Temperature of the water 40o F. Lots 

 180 to 189, inclusive, were milted successively; the first immediately, 

 and the rest at intervals of from half a minute to ten minutes after they 

 were placed in water. The result was as follows, viz, in the lot milted 

 immediately, 97^ per cent, fecundated ; at the end of half a minute after 

 application of water 92^ per ceut. fecundated ; at the end of one minute 

 95 per cent. ; at the end of two minutes, 77^ per cent. ; at the end of 

 three minutes, 80 per cent.; at the end of four minutes, 85 per cent. ; 

 at the end of five minutes, 87^ per cent. ; at the end of six minutes, 85 

 per cent.; at the end of eight minutes none fecundated ; at the end of 

 ten minutes 2i percent, fecundated. 



The inequality of these results may be attributed to minor differences 

 in the njode of manipulation ; for instance, the difference in the shape of 

 the dishes used, in the quantity of water applied, and in the amount of 

 agitation given to the eggs. In experiments 2, 3, and 4, the dishes 

 were broad and shallow, and the quantity of water liberal. In experi- 

 ment 6 the dishes were small mugs, and the quantity of water propor- 

 tionably small. In the case of lot 189, perhaps the stirring given before 

 the milt was applied was insufficient to give the water access to those 

 eggs which lay in the bottom of the mug, and that they, therefore, 

 retained the susceptibility of fecundation for some miuutes longer than 

 they would have done if pure water had had free access to them. 



