of the Salmon in Fresh Water. 121 



only two fish, which were both caught in August . He did not make 

 such estimations of fish in the later months with developed genitalia, 

 hut from other observations he argues, that these two fish should have 

 lost a certain quantity of proteid from their muscle, and have gained a 

 certain amount in their gsnitalia, and from this calculation he strikes a 

 balance. But the second factor of this comparison, the condition of the 

 later fish, being more or less hypothetical, cannot be considered 

 sufficiently definite; his balance can only be accepted as a probable but 

 not as an absolutely proved one. 



Thanks to an ample supply of material from the fishery Board, this 

 investigation has been much fuller than Miescher's. A series of fish from 

 the upper and lower waters, at different seasons, have been analysed and 

 compared by the method already described in the introductory section 

 of this Report. The results obtained enable a fairly accurate balance 

 to be struck. 



The method adopted for estimating the proteid of the organs was to 

 determine the nitrogen contained, and from it to calculate the amount of 

 proteid. This method being generally accepted as the most accurate 

 available, does not require consideration. It gives the maximum 

 possible amount of proteid, but its results are invariably too high, there 

 always being present in tissues some extractive nitrogen. Results are 

 stated as the amount of nitrogen, and changes in the amount' of nitrogen 

 are assumed to indicate changes in the amount of proteid. 



In this section of the Report, when using the term proteid, not only 

 are the true proteid s referred to, but also all albuminoid substances. No 

 attempt has been made in this part of the investigation to separate the 

 various proteids and albuminoids from each other. A study of some of 

 the individual proteids will be found in Dr. Boyd's section of the Report 

 (page 112). 



The nitrogen estimations were made by Kjeldahl's method on the 

 dry residue left after the fats were extracted by ether (vide page 93). 

 Knowing the amount of nitrogen in the dry residue, the amount of dry 

 residue in the muscle or ovaries, and the total quantity of muscle or 

 ovaries, the total amount of nitrogen in the muscle or ovaries of the 

 fish is readily calculated. Thus, for an example : 



Fish 36. Ovary weighs 126 grms., the dried residue of this after the 

 extraction of fat was 2 9 -3 per cent., and was found to contain 12*98 per 



. - , 12-98x29-3 , Q 

 cent, nitrogen. Ihe ovary consequently contained - o o 



per cent, of nitrogen, and total amount of nitrogen in the ovary was 

 3-8x126 



= 4 ' 13 grms - 



In the following Tables will be found the results of the analyses. In 

 them the fish have been classified in the same manner as in the earlier 

 sections of this work. The first group considered are the female fish of 

 1896, next the male fish of 1896, then the fish caught in 1895, and 

 lastly kelts. The 1896 females are taken up first, because they form 

 much the largest group. 



