SALMON. 29 



day. On the 24th of May, twenty-seven days after 

 being hatched, the young fish had consumed the yolk 

 which remains attached to the lower part of the body, 

 and which serves him for nourishment, and the charac- 

 teristic bars of the Parr had become distinctly visible. 

 From a deposition of mud, as Mr. Shaw apprehends, all 

 these fry, except one individual, were found dead at the 

 bottom of the ponds, so that there was no opportunity of 

 watching their future progress ; but an ingenious experi- 

 ment was made, which proved that an increased tempe- 

 rature hastened the development of the infant fish. 



But we shall see that Mr. Shaw was too indefatigable 

 to be daunted by such an untoward accident, and that 

 he persevered in his experiments, till his efforts were 

 rewarded by complete success. 



On the 27th of January, 1837, he captured a male 

 fish of sixteen pounds, and a female of eight, and expressed 

 the ova of the female and impregnated it with the milt 

 of the male in the manner above related, and deposited 

 the spawn in this state in a private pond as before, and 

 to which no fish could by possibility have access. 



" On the 21st of March," says Mr. Shaw (that is, 

 fifty -four days after impregnation), "the embryo fish 

 were visible to the naked eye. On the 7th of May 

 (101 days after impregnation), they had burst the 

 envelope, and were to be found amongst the shingle 

 of the stream. The temperature of the water was at 

 this time 43°, and of the atmosphere 45°; and it is 

 this brood which I have now had an opportunity of 

 watching continuously for a length of time, that is, for 

 more than the entire period which was required to elapse 



