366 DISCOVERY REPORTS 



into shoal water. More than half the year is spent in Antarctic waters, where the 

 temperature of the surface water is rarely more than 4° C. and is frequently below zero. 

 The rest of the year is spent in tropical waters, whose temperature may be as high as 

 29° C. The whale's only external protection against cold is the blubber, which is 

 generally beheved to be thickest at the time of migration from the Antarctic to the 

 tropics and thinnest on the return migration. Since whales cannot regulate their tem- 

 perature by the use of sweat glands, it follows that they must be able to modify body 

 temperature greatly by variation of blood supply to the skin, if not by control of basal 

 metabolism. 



Temperature. Some effort was made in South Georgia to determine the normal 

 temperature maintained in Blue and Fin whales. The procedure was to insert a thermo- 

 meter into the longissimus dorsi muscle as near as possible to the vertebral column. 

 This was done while whales were being dismembered at the whaling station. It was 

 found that fresh carcasses cooled little before dismemberment and that a slight but 

 irregular rise in temperature was observed when decay commenced. The average tem- 

 perature of thirty fresh whales was 35-1° C. High temperatures are found near the 

 abdomen, due doubtless to the presence of decaying matter in the stomach and in- 

 testinal tract. Morimoto, Takata, and Sudzuki (1921) quote a body temperature of 

 36-6-36-9° C. from the early work on northern Balaenopterids, but no mention is made 

 of the part of the body in which the temperature was taken. Both these and the South 

 Georgia temperatures suggest strongly that the whale's temperature is lower than that 

 of most mammals. Smith (1895) quotes observations by Seidangrotsky on domestic 



mammals : 



Horse 38-oo-38-2o° C. 



Cattle 3876-38-96° C. 



Swine 39-44° C. average 



Sheep 39-72-40-22° C. 



Basal metabolism. The problem of temperature maintenance and control leads to 

 a consideration of the minimum energy requirements of a whale which would be 

 sufficient to keep the animal alive in a state of rest (basal metabolism). In this respect, 

 as in others, it will be necessary to make constant comparisons with man's physiological 

 properties, partly because human physiology is better known than that of other land 

 mammals, and partly because man in his submarine ventures has attempted to adapt 

 himself by mechanical means to the conditions under which the whale lives. 



One general feature of basal metabolism according to Starling may be applied to 

 whales: "We may say that a warm-blooded animal requires a daily expenditure of 

 about 1000 calories per square metre of body surface to carry out such motor processes 

 as are essential to life" (p. 510). This figure of basal metabolism can be taken as a 

 mammalian constant irrespective of the natural or acquired integument of the animal ; 

 presumably each animal has taken steps according to its environment to provide itself 

 with adequate insulation, such as blubber, fur, feathers, and so forth. Basal metabolism 

 is greater in small animals than in large ones, since in small animals the surface area is 



