44 



Appendices to Twenty-seventh Annual Report 



Report by D. Noel Paton. 



In November 1908, Mr. W. L. Calderwood asked me if I would 

 examine a salmon which had remained for twelve months in a catch-pit 

 from a fish pond without any possibility of procuring food. I very 

 willingly consented to do so, and on November 18th I received the fish, 

 the photograph of which is given on the opposite page. 



It had the appearance of a very thin male kelt. 



Length - - - 72cm. (2 8 J inches) 



Girth - - - 28cm. 



Depth - 12*5cm. 



Weight - - - 2450 grms. (fully 51b.) 



The muscles were pale, but of a distinctly pink colour. The stomach was 

 empty and shrunken. The gall bladder was empty. There was no fat on 

 the pyloric appendages. In the lower bowel there was some dark brown 

 mucus. The testes weighed 36*5 grms. In order to compare the condition 

 of the organs with our previous results (" Report on Investigations on 

 the Life History of Salmon" [0. 8787], 1898, p. 6), the weight of the 

 fish was calculated as per "fish of standard length," 100cm. This is 

 6,488 grms., and the testes, expressed as for per fish of standard length, 

 weighed 96*6 grms. They were therefore considerably heavier than the 

 testes of upper water fish in July and August, and approached in weight 

 the testes of upper water fish in October and November. They had the 

 appearance of being partly shed, and Mr. Calderwood stated that the fish 

 had been used for impregnating ova before it was killed. 



The weight of this fish in proportion to its length was less than that of 

 any of the female kelts previously examined by me, the average of 23 

 such kelts being 7,755 grms. (loc. cit., p. 74), as against 6,488 grms for 

 the present fish. Although I have tried for several years, I have never 

 succeeded in procuring a male kelt for examination. 



Unfortunately, I did not determine the total weight of muscle, but the 

 usual samples of "thick" and "thin" were taken for analysis. The 

 analyses were made for me in the Laboratory of the Royal College of 

 Physicians of Edinburgh by Mr. Alfred Patterson, who had carried out 

 similar analyses in my previous series of observations. He reports as 

 follows : — 



Muscle: Thick. Muscle: Thin. 



Per 

 Cent. 



Fat - Analysis lost. 



Dry Residue after extrac- 

 tion of Fat - 17-13 



Nitrogen in Dry Residue - 2*56 



Protein calculated from 



Nitrogen - - - 16'00 



Per 

 Cent. 



Fat- - - - - 1-85 

 Dry Residue after extrac- 

 tion of Fat - - 15*33 

 Nitrogen in Dry Residue - 2-28 

 Protein calculated from 



Nitrogen - - - 14-25 



A comparison of the results of these analyses with my previous series 

 show that the muscle of this fish is extraordinarily poor in fat, but not 

 markedly poor in proteins. 



The following table gives a comparison of the percentage composition of 

 the flesh of this fish compared with the average percentage composition of 

 female kelts previously examined by me : — 



