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nearest the surface in dark and mild weather ; and nearer the bottom 
when the weather is bright and cold. 
He next enters on the details of the natural history of the herring, 
describing its characteristics and its distinctive difference from other 
fishes of its class. The important question of its food, is elaborately 
examined; and it is shown, as stated to the author by Agassiz, that 
the herring does not confine itself to one species of food, namely 
that the food usually consists of minute Crustacea ; but during the 
spawning season it feeds on sand-eels, the fry of various fishes, and 
even its own spawn. 
The author has ascertained a new and important fact from personal 
observation, regarding the cohesion of the spawn, and the power of 
adhering strongly to substances on which it may be placed, which 
only takes place on the fecundation of the roe by the milt. 
Many writers reiterate the opinion, that the herring is a native 
of the distant northern seas. This the author shows to be an error, 
proving that the fish is a permanent inhabitant of our coasts. 
He, for the first time, gives a complete description of the visits of 
the herring, or its geographical and chronological distribution over 
the surface of the globe, so far as is known ; and his work is the first 
and only one which exhausts the difficult questions which have hitherto 
arisen regarding the most valuable and important fish, which the 
bounty of Providence sends to supply food for the human race. 
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