CURRENTS AND WHALING. 433 



adapted.* During our cruise in the higher southern latitudes, we saw 

 vast numbers of these medusae around and near the icebergs. The 

 quantity was such as to prove conclusively, that it was in the waters 

 of the temperature caused by the vicinity of these masses of ice, that 

 they delight to dwell. Whales were also in abundance, and although 

 principally of the fin-back species, sperm whales were not entirely 

 wanting. 



As regards the medusa, its powers of locomotion are feeble, and 

 confined chiefly to the purpose of rising and sinking at pleasure. If 

 polar currents exist, it must therefore be swept by them from the place 

 of its nativity, and in its passage to lower latitudes, will by its loco- 

 motive power seek strata in the water of the low temperature to 

 which its constitution is best adapted. My attention was drawn to 

 the habits of the whales here in particular, from the novel manner 

 they exhibited of feeding near the surface, instead of diving lower 

 down, as they are usually seen to do in lower latitudes : they were 

 constantly in sight, instead of being only seen at intervals. 



It will be readily admitted that the medusa, like other animals, has 

 its appropriate seasons of procreation, and it will appear probable that 

 the season at which we saw them in such numbers was that in which 

 they are brought forth most abundantly. So also, however low the 

 temperature of the water in which they delight, there is little proba- 

 bility that their increase goes forward when the regions in which we 

 met them are locked up in ice, and the genial light and warmth of the 

 sun is denied them. 



The food of the sperm whale will therefore be borne off to lower 

 latitudes by the polar streams in greater abundance at one season than 

 another, and this former season corresponds with that in which these 

 currents have their greatest force. The sperm whale, it must be ex- 

 pected, will leave the higher latitudes and follow the currents which 

 transport his food. 



In conformity with this view, we find the habits of the sperm whale 

 migratory. The polar currents, as has been seen, disappear from the 

 surface in many cases, but do not cease to flow ; and even when felt 

 both at the surface and below, they will in approaching lower latitudes 

 have their higher temperatures near the surface. The medusa will 

 therefore descend in either case to greater depths, and the whale must 

 dive in quest of the food which in higher latitudes he could find at the 

 surface. We have seen in what a decided manner the polar currents 



* Innumerable animalcule, the appropriate food of the riglit whale, are also found there, 

 as has been seen by our own observations at the south, and those of Scoresby at the north. 



