96 Transactions of the Royal Society of South Africa. 
Cocks, A. H., M.A., F.Z.S., ' The Zoologist,' London, vol. ix, 1885, 
No. 100, pp. 135, 141, 143 ; vol. x, 1886, No. 112, pp. 121, 122, 
128, 129, 136 ; vol. xi, 1887, No. 126, pp. 207, 208, 211, 219, 222 ; 
vol. xii, 1888, No. 138, pp. 201, 202, 204, 206, 208. 
Therefore, in my opinion, the statement that B. borealis was considered 
rare in northern waters is somewhat misleading. 
Feeding habits. — Investigation of the food of whales is a matter of 
vital importance in studying the great question of the migrations of these 
mammals, and it is therefore to be regretted that the statements in the 
note under review about the feeding habits of whales — as to whether they 
are ichthyophagous or " planctonophagous " — are difficult to reconcile with 
widely observed facts. Dr. Peringuey states (p. 74) that B. borealis, B. 
physalus and B. musculus are not planctonophagous, except perhaps occa- 
sionally, whereas, as a matter of fact, all these whales regularly feed on the 
Plankton whilst in South African waters. From an examination of the 
stomachs of some hundreds of specimens of B. musculus, B. borealis and 
B. physalus in South Africa, I am in a position to state definitely that it is 
only on some occasions that fish, or the remains of fish, have been found 
therein, whereas the small crustaceans are invariably present. I have not, 
so far, observed any indication of a fish diet in the stomachs of B. musculus, 
a,nd all available literature refers to this whale as feeding solely on the 
Plankton. In the case of the two other species I am inclined to agree with 
Andrews (' National Geographic Magazine,' Washington, vol. xxii, No. 5, 
p. 427), who states that " The whale-bone whales probably never eat fish 
of any kind if other food is to be had, although there is some evidence that 
B. physalus is in some degree ichthyophagous at certain periods in the 
Northern Hemisphere, this state of affairs being probably due to partial 
failure of the Plankton supply. Ichthyophagous whales are easily identified 
by the presence of fish- scales in the stomach, which scales apparently take a 
much longer time to digest than either the flesh or bones of the fish. On 
the other hand, a Plankton-eating whale is, as a rule, very easily identified 
by the exudation of terra co^a-coloured fasces, but if such be not present, an 
examination of the stomach will instantly determine the question. Dr. 
Peringuey probably knows that I hold no brief for the Norwegian whalers 
to whom he refers (p. 75) as being unreliable, yet if he would go for a trip 
on a whaler, any experienced Norwegian gunner would probably be able to 
show him Fin, Blue and Sie Whales actually feeding on the Plankton. 
If the investigator requires further information about the food of the 
whalebone whales, I would refer him to the following publications : 
D'Arcy, Wentworth Thompson, ' The Scottish Naturalist,' No. 82, 
October, 1918, pp. 232-233. 
Clark, E. S., M.A., B.Sc, ' South Atlantic Whales and Whaling,' 
1919. (Shackleton's 1914-1917 Expedition.) 
