ON FOOD-FISHES. 25 



the Channel, and the incursions of the eastern boats on 

 the west, in addition to the local population. The wonder, 

 perhaps, is lessened when we consider that for five or six 

 hundred years at least the limited area of the estuary of the 

 Thames has been persistently fished for shrimps by man, and 

 that his nets have simultaneously killed the young soles, plaice 

 and dabs throughout this long period without, up to this date, 

 affecting in any marked manner the prevalence of either 

 crustaceans or fishes. The independence of nature in the sea 

 and man's helplessness are further shown in connection with 

 the swarms of dog-fishes that occasionally occur in the north- 

 west and in the south, and which ruin his captured fishes and 

 nets. 



Step by step we have thus briefly passed under review the 

 whole series — from minute floating plants and invertebrates to 

 fishes, and find that they constitute a complex cycle, linked 

 together in intricate bonds, indissoluble by any agency man 

 can devise. Even in the most insignificant group, the opera- 

 tions of nature are on a scale which forbids the possibility of 

 human intervention. Only in certain species exposed by the 

 tide or which frequent shallow water and are easily operated on 

 by man's agency, or are under special conditions in deep water, 

 has the effect been evident. All the rest on a free sea-board 

 appear to resist attempts to reduce to vanishing point or to 

 increase, some becoming for the moment rare or altogether 

 absent, and, just as their doom has been pronounced, reappear- 

 ing in countless multitudes on the same sites. 



The survey of the sea and its inhabitants, therefore, in the 

 main affords no grounds for pessimistic views, but, on the 

 contrary, conduces to reliance on the resources of nature (by 

 which we mean Divine Providence) in this vast area. Genera- 

 tions of men may weave their theories and propound their 

 generalizations, but century after century the oceanic plants 

 and animals maintain their abundance and demonstrate their 

 independence of all artificial regulations. On our shores it 

 may be wise or it may be politic to make such regulations, yet, 

 speaking generally, they seem to have but a feeble effect on the 

 great laws of nature, and especially on the wonderful cycle of 



