134 Dr. Mac Culloch on the Use of 



sufficient. Let me be permitted, therefore, to suggest what I 

 consider more likely to be successful, premising also a few 

 remarks, which are, however, unfortunately little more than 

 hints and conjectures. 



I have shewn on a former occasion, in your Journal, that the 

 changes of the herring, as to place, are even more capricious 

 than those of the pilchard have ever been, while in some cases 

 also their abandonment of particular shores has proved parti- 

 cularly durable. Nor is this less true of all fishes, though most 

 conspicuous in the gregarious ones. The cause would concern 

 us more, could we find the remedy ; though we cannot, it is 

 still an object of rational curiosity. And it probably consists 

 in previous change of place, or deficiency in their natural 

 food, though of this we can equally give no account, and have 

 only removed the difficulty from one set of animals to another. 

 That the occasional disappearance or diminution of gregarious 

 fishes, perhaps in particular, is also sometimes dependant on 

 epidemic, or epizotic disease, I have suggested to be probable 

 in another work, but cannot enlarge on it here. 



Now, as to the actual fact of the variable presence or abun- 

 dance of those endless and multitudinous marine animals which 

 are probably the food of various fishes, there can be no doubt, 

 although naturalists, like fishermen, have seemed to pay no 

 attention to it ; nay, not even to the existence of such animals ; 

 and after all their voyages and studies, have utterly overlooked, 

 not ninety-nine in a hundred, but far more, even of those which 

 swarm about our own shores, to say nothing of the vast ocean 

 through all parts of the world, which they have traversed on 

 these very pursuits. My own experience is narrow, but it is 

 at least sufficient to establish the point. And the general result, 

 as it bears on this question, is, that having discovered nearly 

 two hundred undescribed species, rather by accident than de- 

 sign, since it was not my pursuit, in the short space of six 

 weeks, and with a very few hours of those weeks, on a very 

 limited tract of coast ; and further found that in such places the 

 whole sea was almost a mass of life, it cannot but follow that, con- 

 sistently with the universal order of nature, these are the very 

 food of the other tribes which exceed them in magnitude, and 

 that here, probably, in particular, the great armies of the grega- 



