NATURAL HISTORY OF THE SALMON. 41 



montfield ponds. Ova were deposited on the 23d of 

 November ; by the end of March the fish began to issue 

 from the eggs ; and that process was entirely completed 

 before the end of May the hatching thus appearing to 

 require from about 90 to 130 days, a result agreeing 

 with that arrived at by Mr. Shaw ; but the length of this 

 period may be regarded as depending very much on 

 various circumstances, especially the temperature of the 

 water, as varying with each season and with the month 

 in which the ova happened to be deposited. There is 

 agreement this far, and also this much further, that the 

 fish hatched, say in March, remain in the river (though, 

 partly from minuteness, partly from shyness, rarely 

 visible before July) until April or May of the following 

 year that is, till from between thirteen and fifteen 

 months after they have left the egg. It is here that the 

 question arises, Does the parr assume the migratory dress 

 and movements then, or a year afterwards ; i. e., at the 

 age of about one year and two months, or at the age of 

 about two years and two months ? The doubt on this 

 point, oddly enough, was incidentally raised, though it 

 was also claimed to have been settled, by Mr. Shaw. 

 When he began his experiments, he had in view only 

 the question as to the identity of the parr and the young 

 of the salmon, and would appear to have had no doubt 

 that the young of the salmon descended to the sea in the 

 spring of the year following that in which they had been 

 born ; and the facts apparently to the contrary, and also 

 another and now apparently undisputed discovery, re- 

 garding the apparently premature sexual maturity of 

 male parrs, came upon him, so to speak, by accident and 





