446 THE POPULAR SCIENCE MONTHLY. 



that lean and depauperated state which makes a " shotten herring " 

 proverbial. In this condition it answers to the salmon " kelt," and the 

 milt or roe are now shrunk and flaccid and can be blown up with air 

 like empty bags. If the spent fish escapes its myriad enemies, it doubt- 

 less begins to feed again and once more passes into the matie state 

 in preparation for the next breeding-season. But the nature of this 

 process of recuperation has yet to be investigated. 



When they have reached the matie stage, the herrings, which are at 

 all times gregarious, associate together in conspicuous assemblages, 

 which are called shoals. These are sometimes of prodigious extent 

 indeed, eight or nine miles in length, two or three in breadth, with an 

 unknown depth, are dimensions which are credibly asserted to be some- 

 times attained. In these shoals the fish are closely packed, like a flock 

 of sheep straying slowly along a pasture, and it is probably quite safe 

 to assume that there is at least one fish for every cubic foot of water 

 occupied by the shoal. If this be so, every square mile of such a 

 shoal, supposing it to be three fathoms deep, must contain more than 

 500,000,000 herrings. And when it is considered that many shoals 

 approach the coasts, not only of our own islands, but of Scandinavia 

 and the Baltic, and of Eastern North America, every spring and au- 

 tumn, the sum total of the herrings which people our seas surpasses 

 imagination. 



If you read any old and some new books on the natural history of 

 the herring, you will find a wonderful story about the movements of 

 these shoals : how they start from their home in the polar seas, and 

 march south as a great armada which splits into minor divisions one 

 destined to spawn on the Scandinavian, and one on our own shores ; 

 and how, having achieved this spawning raid, the spent fish make their 

 way as fast as they can back to their Arctic refuge, there to rei3air 

 their exhausted frames in domestic security. This story was started 

 in the last century, and was unfortunately adopted and disseminated 

 by our countryman Pennant. But there is not the least proof that 

 anything of the kind takes place, and the probabilities are wholly 

 against it. It is, for example, quite irreconcilable with the fact that 

 herring are found in cods' stomachs all the year round. And the cir- 

 cumstance to which I have already adverted, that practiced eyes dis- 

 tinguish local breeds of herrings, though it does not actually negative 

 the migration hypothesis, is very much against it. The supposition 

 that the herring spawn in the north in the early spring, and in the 

 south in the autumn, fitted very well into the notion that the vanguard 

 of the migrating body of herrings occupied the first spawning-ground 

 it reached, and obliged the rest of the horde to pass on. But, as a 

 matter of fact, the northern herrings, like the southern, have two 

 spawning-times ; or perhaps it would be more correct to say that the 

 spawning-time extends from autumn to spring, and has two maxima 

 one in August-September, and one in February-March. 



