ANt> TSETE distribution AT DIFFERENT AGES. 115 



specimens, 12 inches to 2 feet long, are occasionally taken in the 

 great trawls, but of the other species many one-year-old individuals 

 are destroyed by them. It is remarkable also how commonly one- 

 year-old dorys are taken in the deep-sea trawls. 



Practical Considerations. 



A great deal of work remains to be done before we obtain an 

 adequate knowledge of the life-histories of our valuable sea fishes. 

 I hope to continue my own observations in various directions, and in 

 future to add largely to the data recorded above. But in the mean- 

 time the question of the harm done to our sea fisheries by the de- 

 struction of under-sized or immature fish is constantly being 

 agitated, and cannot be too carefully considered. Our national 

 statistics show that our best sea fish are getting scarcer. It seems 

 at first sight the irony of fate that the finest fish such as sole, 

 turbot, brilT, and dory should be scarce, while inferior kinds such 

 as dabs are plentiful, and worthless kinds such as scald-fish and dog- 

 fish are still more abundant. The case of the sole is difficult to 

 explain. It feeds on worms chiefly as do the plaice and flounder, 

 yet it is by no means so plentiful as the plaice. One might be 

 tempted to maintain that the sole is really no better intrinsically 

 than the plaice, but only valued more because it is dearer. But a 

 moment^s consideration of the difference between the flesh of the 

 two is enough to dispel such an idea. In the case of the turbot, brill, 

 and dory, however, there is a reason why they are relatively scarce. 

 These fishes, compared with many other kinds, are as the Carnivora 

 to the Herbivora on land. They feed exclusively on other fishes. 

 They are fishes of prey, and must, therefore, as in the case of other 

 Carnivora, exist in smaller numbers than the fish they prey upon. 

 Perhaps some day we shall also be able to understand why the sole 

 is less abundant than the plaice. 



But the practical question is how to prevent the decrease in the 

 supply of fishes whatever their natural numerical proportions to one 

 another, and one obvious precaution is to prevent as far as possible 

 the destruction of the young. I will, therefore, here indicate the 

 bearings which my observations at Plymouth have upon this practical 

 question. Dr. Fulton, throughout the whole of his inquiry, has 

 interpreted the term immature fish as meaning a fish not yet capable 

 of reproduction. The fishermen of the east coast, who have been so 

 strongly moved on the subject of immature fish, knew nothing and 

 cared nothing about the size at which a fish of a certain kind began 

 to breed. What they were thinking of was the fact that if all the 

 small fish were caught there were none left to grow lai'ge, and con- 



