American Fisheries Society 21 S 



The deduction from all this is obvious. Life in the 

 seas, as elsewhere, must be regarded not as sets of unrelated 

 phenomena, but as a totality, a unit, composed of interlock- 

 ing parts or associations, centering around various condi- 

 tions of habitat, but yet overlapping into and reacting upon 

 each other. From this point of view no species or group 

 of species can be considered without reckoning in its entire 

 environment; no animal, no matter how valueless it may 

 superficially appear, can on that account alone be consid- 

 ered insignificant in the economy of nature, nor for that 

 matter in the economy of mankind. For man himself 

 stands to the totality of the living world precisely as any 

 other species of animal, except perhaps in that he is its 

 greatest disturbing factor. 



No one knows better than the fish-culturist how impos- 

 sible it is to consider our food-fishes apart from their food 

 and their enemies. The balance must be made to weigh 

 in favor of the food supply until the race is propagated, 

 or that race will be exterminated by its enemies. There- 

 fore is it not just as important to consider the food of the 

 food of the food-fishes and the enemies of their enemies? 

 The whole is a connected and inseparable series. And dis- 

 turbance in a single link of the chain must be felt along the 

 whole line. 



Inasmuch as the lower inverbrates, including the plank- 

 ton, form such a close connection with the food supply of 

 our fisheries, the writer believes that a series of ecological 

 studies concentrated on typical invertebrate habitats along 

 our coast would go far toward increasing our knowledge 

 of this great food source and its practical application to 

 the fisheries, to say nothing of the purely biological prob- 

 lems involved. How interesting are these latter problems 

 is well shown by C. B. Davenport in his interesting paper 

 entitled 'The Animal Ecology of the Cold Spring Sand 

 Spit."* 



* Decennial Publications of University of Chicago, vol. x, pp. 

 157-176. 



