304 MR. SHAW'S SALMON EXPERIMENTS. 



the body of the female, from the male In the same 

 way he expressed the milt, and with it impreg- 

 nated the ova, which he transferred to one of his 

 prepared ponds. On the 28th of April following, 

 one hundred and fourteen days after impregnation, 

 the young salmon were excluded from the eggs, 

 but were not so on the day preceding. 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 for the purpose of nourishment, and the 

 characteristic bars of the parr had become dis- 

 tinctly visible. An accidental deposit of mud 

 destroyed these fry. In the same year on the 

 27th of January, he made a duplicate of the 

 above experiment, and found on the 21st of March 

 (fifty-four days after impregnation) that the em- 

 bryo fish were visible to the naked eye. On the 

 7th of May (one hundred and one days after im- 

 pregnation) they had burst the envelope, and 

 were to be found amongst the shingle of the 

 stream. The temperature of the water was at 

 the time 43, and of the atmosphere 45 ; and 

 this brood Mr. Shaw had an opportunity of watch- 

 ing continuously for a length of time, for more 

 than the entire period which was required to 

 elapse from their exclusion from the egg, until 

 their assumption of those characters which dis- 



