290 TRANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



The North Sea herrings were also abnormal in quality in 

 1921. Thus a packer of tinned herrings of high grade says : 

 " This year's pack has something the matter with it. The 

 flesh of the fish is grey to brown instead of light, like a chicken. 

 The liquor in the tin is watery and dark and bitter instead of 

 light, thickish, and pleasing to smell and taste. " These defects, 

 it must be understood, were comparative ones, for even this 

 1921 pack of herrings were, to the ordinary person, of very 

 high quality. Nevertheless, to the trained eye and palate the 

 result of the packing operations was inferior to that of 1920. 

 Why? 



What one heard about was, on many sides, the " still and 

 dirty " water (which meant unusually large quantities of plank- 

 ton organisms). The abundance of oil was also blamed, and 

 the mines and dumped explosives which were " exuding their 

 filthy, deleterious chemical compounds to the detriment of the 

 plant life upon which the little animals forming the herring's 

 food, feed." 



It is, of course, quite impossible to say, with the information 

 that we have, whether the general poverty of nutrition charac- 

 terising many fish, at certain times of the year, was due to any 

 one, or several of the suggested causes. The ulcerated cod 

 which are described here may have been such because of some 

 form of poisoning due to the presence of products of decom- 

 position of explosives. Not all these sores were septic, and 

 in some there was little indication of organisms in the pus. 

 It is possible to produce a septic pus by the local action of 

 various chemicals, such as mercury and copper and their salts, 

 and so some of the ulcerated fish may have become so by such 

 means. Still other sores were certainly septic, so that, on the 

 whole, it is not possible to state definitely what were the causes 

 of the lesions. 



