General information with regard to such animals is useful, however, as
showing the relative abundance of plankton on which the whales feed in
the ocean. There are, for instance, more whales in the Antarctic than in
warmer seas; and some whales at any rate (e.g. Humpback whales) probably
come north into warmer waters in the winter rather for breeding purposes
than to get food.[39]

With regard to dolphins four species were observed beyond question. The
rarest dolphin seen was Tersio peronii, the peculiarity of which is that
it has no dorsal fin. This was seen on October 20, 1910, in latitude 42°
51´ S. and longitude 153° 56´ E.

Reports of whales and dolphins which are not based upon carcases and
skeletons must be accepted with caution. It is most difficult to place
species with scientific accuracy which can only be observed swimming in
the water, and of which more often than not only blows and the dorsal
fins can be observed. The nomenclature of dolphins especially leaves much
to be desired, and it is to be hoped that some expedition in the future
will carry a Norwegian harpooner, who could do other work as well since
they are very good sailors. Wilson was strongly of this opinion and tried
hard to get a harpooner, but they are expensive people so long as the
present boom in whaling lasts, and perhaps it was on the score of expense
that the idea was regretfully abandoned. We carried whaling gear formerly
taken on the Discovery Expedition, and kindly lent for this expedition by
the Royal Geographical Society of London. A few shots were tried, but an
unskilled harpooner stands very little chance. If you go whaling you must
have had experience.

The ship was not slowed down to enable marine biological observations to