ATKINS THE SALMON AND ITS ARTIFICIAL CULTURE. 259 



6.— THE SUSCEPTIBILITY OF EGGS TO FECUNDATION OUT OF WATER. 



Experiment 7.— Lot 67 stood long before milting or watering ; rate of 

 fecundation, 100 per cent. 



Experiment 8. — Lot 92 stood witlioiit milt, while lot 93 was taken and 

 milted ; rate of fecundation, 100 per cent. 



Experiment 9.— Lots 133 and 134 were kept in a pan half au hour 

 before milt was applied, and the rates of fecundation were 90 and 80 

 per cent, respectively. In the former case water was applied as soon as 

 usual ; in the latter case the eggs, with the milt, were carried without 

 water to the hatching-house, and turned directly into the troughs. 

 This circumstance is not, however, believed to have been influential, 

 for in other cases it was found to make no difference. (See lots 129 to 

 132, in table 9.) That the eggs themselves were healthy is proved by the 

 successful fecundation of the remainder of the eggs from the same fish, 

 by the ordinary method, the rate in all being 100 per cent. 



Experiment 10.— The eggs were taken from a healthy fish, and part of 

 them (lot 210, containing 4,400 eggs) milted at once with complete 

 success. The remainder were kept in the hatching-house in a pan 

 covered over, but not secluded from the air. At the end of twelve 

 hours, thirty hours, two days, and four days, successive lots (225, 

 229, 234, 250) were taken from this pan, and milted with fresh milt. 

 The rate of fecnndatiou was as follows : at the end of twelve hours, 90 

 per cent. ; thirty hours, 87^ per cent. ; two days, 75 per cent. ; four 

 days, 12} per cent. 



The relsults above stated show that the egg retains the susceptibility 

 to fecundation for several days, under favorable circumstances, but that 

 in some cases a considerable percentage loses it in half au hour. 



7. DURATION, IN AIR, OF THE FECUNDATING POWER OF THE MILT.. 



Experiment 11.— Lot 76 : milt taken ten minutes before its applicatioa 

 to the eggs ; fecundation, 92i per cent. 



Experiment 12.— Lot 85 : milt taken from the fish several hours ia 

 advance, and kept in an open dish ; fecundation, 100 per cent. 



Experiment 13.— Lot 249 : milt kept four days before application ; 

 fecundation, none. This total failure is supposed to have been the 

 fault of the milt, since some of the same eggs treated with freshly-takea 

 milt were fecundated. (See lot 250.) 



8.— DURATION, IN WATER, OF THE FECUNDATING POWER OF THE. MILT'^ 



Several extensive experiments were undertaken for the purpose of 

 determining this point, but accident frustrated them, and they are not 

 reported. But it may be stated, in general, that milt was found to- pre- 

 serve its efficiency for several minutes after being placed in water. 



