CURRENTS AND WHALING. 
483 
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 w r ere 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 animalculse, the appropriate food of the right whale, are also found there, 
as has been seen by our own observations at the south, and those of Scoresby at the north. 
