of the Fishery Board for Scotland. 103 
It is possible that for a short time (a month perhaps) after spawning 
the herring does not take food. 
There are without doubt similar periods during the reproductive life 
of herrings from all districts. Heincke’s statements with regard to the 
storage and using up of the muscle fat were based on no analytical 
evidence. 
There are still many points in connection with variations in the 
metabolism in herrings during spawning which require to be worked out, 
especially the cycle of phosphorus between muscles and ovaries. 
Before concluding, I should like to refer to a subject which is at 
present attracting a good deal of attention, namely, the nutritive value 
of spent herrings. 
Statements are made vaguely as to the unwholesome character of the 
spent fish. Now, upon what foundation does this rest? Usually upon no 
further evidence than the general appearance of the flesh of the fish, 
which is undoubtedly poorer in fat than in the maturing herring. But 
the nutritive value of the fish does not depend solely upon the fat which 
it contains; the percentage of proteid must also be considered, and if the 
tables of analyses be consulted, it will be seen that in this respect the 
spent fish compare by no means unfavourably with the maturing or 
mature fish. 
But there is one other point which one must bear in mind, namely, 
that in many cases spent fish contain a large percentage of fat in their 
muscles, and to illustrate this I include some tables of analyses of fish 
caught in Loch Fyne in May and June of this year. In many cases 
these were fish which were undoubtedly storing fat after the discharge of 
ova had taken place. It is true that this storage of fat does not take 
place to any marked extent until three or four months have elapsed since 
the last spawning took place, but still the herrings present the appearance, 
so far as the genitals are concerned, of spent fish. 
Again, the poverty of fat in the muscles of freshly spent herring may 
render them more digestible in the case of some individuals at least. 
One must also remember that fully mature fish about to spawn are in 
much the same condition as freshly spent fish (vide Helmsdale herrings, 
December 6), and yet these fish would scarcely be termed unwholesome. 
It would have been of extreme value to have had analyses made of 
herrings which had left Loch Fyne in January and gone to Kilbrannan 
Sound and Campbeltown district; but unfortunately I was unable to 
obtain specimens. 
I subjoin the analyses to which I have just referred. 
Attention may be specially directed to the analyses of the flesh of the 
large spent fish of June 2, as these show a comparatively high fat 
percentage. 
May 16, 1906. 
The herrings sent on this date from Ardrishaig were young immature 
fish. The genitals of 16 of these herrings weighed only 2:15 grammes, 
and the ova were exceedingly small, ‘(05—-08mm. 
| TABLE. 
