58 SALT-WATER FISHES 



Calandruccio, Agassiz, to mention only a few, from other seas 

 have bridged many of the widest gaps in our knowledge as it 

 was when Day wrote his laborious and still standard work ; but 

 full as many mysteries await explanation. The man who knows 

 most best appreciates the extent of his own ignorance, and the 

 interesting communications to the Journals of the Marine 

 Biological Association, and similar publications, are not only 

 one long cry for further research, but breathe a spirit of doubt 

 and reservation that we seek in vain in the positive pronounce- 

 ments on migrations and development in the books of fifty 

 years ago. The older writers knew ; the modern investigator 

 thinks : the more enquiry proceeds, with all the facilities 

 afforded by modern tow-nets and apparatus for dragging the 

 secrets from the greatest depths of ocean, the more scientific 

 men will say they only think, but the more in reality they will 

 know. 



The exhaustion of our fisheries, more particularly the 

 sensible depletion of the inshore grounds and consequent need 

 of going further and further from home to supply the market, 

 increasingly occupied the attention of politicians, biologists, 

 and men of commerce during the last decade of the nineteenth 

 century, but a satisfactory solution of the difficulties has been 

 left for the twentieth. Thoughtful studies have been pub- 

 lished embodying a divergence of opinions. In his Resources 

 of the Sea, Professor W. C. Mcintosh, whose joint work 

 with Mr. Masterman* has been one of the chief sources of 

 information in the preparation of this volume, practically 

 endorses the laissez-faire views of Huxley, who saw in the sea 

 a large source of supply with as good (and apparently also as 

 many) fish in it as ever came out of it. On the other hand, 

 Mr. E. W. L. Holt, who has given much attention to these 

 matters, teUs us in his study of "The Grimsby Trawl Fishery 

 and the 'Destruction of Immature Fish that the North Sea is 



* The Life-Histories of the British Marine Food-Fishes. Where 

 reference is made to these authors, this is the work referred to. 



