Dr. Mac Culloch on the Herring. 219 



our attempts. This was well known in Pennant's time, and long 

 before, since it is a fishery of a very ancient date ; and it ought to 

 have prevented the promulgation of the absurd theory which I have 

 here contested. It is now equally known to ourselves, from our 

 own deep sea fishery ; though that is comparatively little pursued, 

 for reasons which will appear hereafter. 



The approach to the shores is performed, in the first place, for 

 the purpose of spawning, as this operation can only be carried 

 on in shallow waters ; and hence the resort of the fish to the lochs 

 and bays. It is probable also that the pursuit of food is another 

 reason or motive ; and, among that food, we may reckon the 

 medusae and other analogous marine vermes, which are produced 

 in such abundance during the summer, in all these shallow seas. 

 Nor is it unlikely that the herrings are driven in to the coasts 

 by their enemies, the piked whale, the grampus, and the fin-fish, 

 as well as by the cod and other smaller fishes that make prey 

 of them. 



If all these motives variously combined will not account for their 

 irregularity, they may at least aid in doing so. Hence, its haunts, 

 as well as its periods may vary. That the season of spawning in 

 different fish takes place at different periods, is apparent from the 

 different states as to fulness in which these are taken at the same 

 time. Hence the periods of their approach to the shores must 

 vary, and hence also the full growth of the young fish must be 

 established at different periods. As to the food, the season and 

 place in which that is produced is known to vary, as does its abun- 

 dance ; and this, unquestionably, must be one of the powerful 

 motives by which their appearance both as to time and place is 

 regulated. The appearance of their great enemies is no less un- 

 certain, and thus also we approximate somewhat nearer to the 

 causes of all these variations. Since there is reason to believe 

 that the herrings feed on the medusas, and as the presence of these 

 is known by the luminous state of the water, it is very likely that 

 this might, in itself, form some guide to the fishermen for their 

 presence. But as they have not hitherto been aware of the cause 

 of the luminous state of the water, this indication has been neg- 



