12 



Part III. — Twenty-fourth Annual Report 



The Food-Value of the Herring. 



As part of the series of researches now being carried out by the 

 scientific department of the Board on the herring and herring 

 fisheries, it was decided to obtain analyses of herrings in order to 

 determine their composition and food-value at different periods of 

 their development, especially when ripe or nearly mature and when 

 spent. Thi3 investigation was undertaken by Dr. T. H. Milroy, 

 Professor of Physiology, Queen's College, Belfast, who furnishes an 

 important paper on the subject which is contained in the present 

 Eeport, the detailed analyses being set forth in numerous Tables. 

 Herrings have been analysed before, but the results have shown 

 much discrepancy from the fact that the season of the year or the 

 sexual development of the fish has been ignored. Professor 

 Milroy shows that great differences in the muscle of the herring 

 exist at different periods, even when the herrings are taken from 

 the same waters. The herrings used for the research were obtained 

 principally from Lochfyne, but also from Lochboisdale and Helms- 

 dale. 



The composition of the herrings is stated in terms of water, 

 proteid, fat, and phosphoric acid, and as the muscle or flesh 

 constitutes the main source of the nutritive value of the herring, it 

 is important to recognise the variations in its composition. These 

 are most striking, especially as concerns the percentage of fat, and 

 as this food principle possesses such a high caloric value, any 

 marked decrease in its amount lowers the nutritive value of the 

 fish to a serious extent. The lowest fat-percentage was found in 

 the large spent herrings from Lochboisdale in February, and the 

 total amount of fat present in the collective muscles of the average 

 fish was exceedingly small. In these muscles the percentage of 

 water was higher than normal, but the proteid and phosphorus 

 percentages were but little affected. In Lochfyne, the fat-per- 

 centage of the fiesh of the herring continues to rise during August, 

 September, and October. It begins to fall slowly in November, 

 markedly in December, most markedly during spawning, and 

 continues at a low level until the fish begin to feed again. 



With regard to the nutritive value of spent herrings, Professor 

 Milroy says the statements often vaguely made as to their 

 unwholesome character usually rest upon the general appearance 

 of the flesh, which is undoubtedly poorer in fat. But the nutritive 

 value depends not only upon the fat, but upon the proteids, and 

 the analyses show that in this respect spent herrings compare by 

 no means unfavourably with the maturing or mature fish. Fully 

 mature fish, about to spawn, are in the same condition as freshly 

 spent fish. 



A similar research on the composition of the herrings of the 

 east coast of Scotland is now in progress. 



The PiAte of Growth and Age of the Hekring. 



To the present Keport a paper is contributed by Dr. Wemyss 

 Fulton on the growth and age of the herring, based upon the 

 measurements and examination during the last six years of nearly 



