86 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
sardines because they were very fat while the winter-caught 
fish had a lower commercial value.* Of course the variation 
was also studied in a strictly scientific manner. 
A similar variation was expected in the case of these Manx 
herrings. It was expected that the percentage of oil in the 
flesh would be small at the beginning of the fishery (in May), 
would rise with the increase of sea temperature and attain a 
maximum in August, and then would fall rapidly as the sea 
temperature decreased, and as spawning occurred. Such 
a metabolic cycle was found to exist, but the change in fat# 
contents was very much greater than previous work had led 
us to expect. 
In the course of the investigation the dietetic aspect became 
a very obvious one to take up, and so the analyses, which at 
first dealt only with fat-contents, came to include the other 
“ proximate food stuffs.” 
The investigation was extended to include herrings from 
other sources than the Manx fishery, cured fish, and sprats. 
It is not pretended that this research is complete, yet a greater 
amount of information is now available than has so far been 
in the possession of food investigators. It will be seen from the 
data given here that simply nothing is conveyed by any state- 
ment of the food value of “ the herring ” ; the kind of fish must 
be specified before we can say what it is worth from the point 
of view of nutrition. 
Finally there are the physiological problems—by far the — 
more interesting ones. The seasonal changes that occur in 
the body of a fish were worked out by Miescher Reusch, in the 
case of the Rhine Salmon, and by Noél Paton and his colleagues 
in the case of Salmon from the Scottish coasts. It cannot be 
said that so much has been done, with regard to the salmon, 
* All the British sprat-fisheries are winter ones and the fish, being rela- 
tively poor in fat, are inferior to the Norwegian brisling. Where are the 
British sprats in summer? At present there are no fisheries, and if there - 
were the industrial (and food) resources of this country would be considerably 
increased. 
