Dr. Knox on the Food of certain Gregarious Fishes. 59 



the fish in prime condition. Of this truth the deep-sea fisheries of 

 Cod and Haddock, as compared with those caught high in estuaries, 

 also afford good examples. A long series of observations, establishing 

 this position in regard to the Herring, are then given. And lastly. 

 Dr. Knox states that his friend and former pupil, Mr. H. D. Goodsir, 

 one of the enterprising companions of Sir John Franklin in his last 

 fatal expedition, having been requested by him to push the inquiry 

 to the utmost, that lamented naturalist undertook a series of excur- 

 sions in the fishing-boats, not only in the Frith of Forth, but also to 

 the fishing-ground near the Isle of May, and in the open sea. The 

 author transcribes one of Mr. Goodsir's letters, dated " Anstruther, 

 June 15, 1843," in which he states, first, that "the Entomostraca 

 are at certain seasons the almost exclusive food of the Herring. 

 There can be no doubt that they follow shoals of these Crustacea 

 to prey upon them, for it is only when the latter make their a])- 

 pearance on this coast that the former are seen, and when the 

 food is most plentiful the Herrings are in best condition. It is 

 during the summer months also that we find the lan'se of the more 

 common species of Decapoda, along with those of Balani, and occa- 

 sionally a minute shell-fish, among the contents of the stomach. 

 Secondly, it appears to be chiefly during the winter and spring 

 months that the Herrings take other kinds of food than the Ento- 

 mostraca ; during these months we find the stomach oftener empty, 

 and only occasionally filled with Crustacea, such as shrimps, &c. ; 

 in other cases with Entomostraca. Thirdly, as to Entomostraca 

 being the partial or exclusive food of other fish besides the Herring, 

 there can be no doubt that during the summer months, when the 

 shoals of Entomostraca, or what our fishermen term Maidre, are in 

 gi-eat abundance, they form the food of a great number of other 

 animals besides the Herring. The common Coal-fish is particularly 

 the species which, next to the Herring, preys on the Maidre. It 

 appears to me also that the shoals of Cetacea, which make their ap- 

 pearance in the Frith during the Herring season, are in pursuit of 

 the Maidre, and not of the Herring, as is most generally thought." 

 To these facts, thus confirmed, Dr. Knox would especially call the 

 attention of M. Valenciennes ; they are most important to man in 

 regard to the Herring-fisheries, and explain certain ceconomic sta- 

 tistics bearing on the great fisheries of Holland, otherwise wholly 

 unintelligible. The naval power of the ancient Republic of Holland 

 was connected with, and based on, a deep-sea Herring-fishery ; while 

 the modern Herring-fisheries of France and England and the Scan- 

 dinaAaan States are shore- and boat-fisheries, of little value as a food- 

 producing employment, and of no value whatever in a naval point of 

 view. Dr. Knox concludes this branch of the subject with extracts 

 from the works of Sir Gilbert Blane, Dr. M'Culloch, and Leeuwen- 

 hoek, showing the total obscurity in which the food of the Herring 

 was involved prior to the time when he first communicated the 

 result of his observations. 



Lastly, the author proceeds to examine the question as regards 



