THE COMPOSITION OF WHALE MILK 



473 



more difficult for the hydrochloric acid, which is added in the fat analysis, to break up 

 the protein masses which occlude the fat globules, and in this way the result for the 

 fat content is liable to be too low in a formalin-preserved sample. 



The usual routine analyses for milk were employed, the Werner-Schmid process 

 being used for the fat content analysis. A summarized account of the methods is given 

 later. 



The following results were obtained at South Georgia : 



South Georgian whales (results expressed as percentages) 



Comparison of the above three analyses may be made with the following results, 

 which represent all the cetacean milk analyses I have been able to find in the literature : 



Results taken from other observers' papers (results are percentages) 



1. Porpoise, Delphinus phocaena, T. Purdie, Chem. News, vol. 52, p. 170, 1885. 



2. Bottle-Nose whale, Globicephalus melas, Frankland and Hambly, Chem. News, vol. 61, p. 63, 1890. 



3. Blue whale, Balaenoptera sibbaldi, Backhaus, Molkerei Zeit., Berlin, vol. 14, p. 481, 1904. 



4. Bartenwal (Whalebone whale), Schreibe, Miinchener Mediz. Wochenschrift, vol. 55, p. 795, 1908. 



High percentages for the fat and the solids not fat are immediately noticed in both 

 sets of figures. Cetaceans have a large amount of blubber tissue to keep up the blood 

 heat and form a reserve of combustible material for times when intensive feeding has 

 ceased and foodstufl^s are absent ; and presumably the richness of cetacean milk in fat 

 and solids not fat is entirely due to the needs of the young calf for food with a high 

 fat and sugar content. It will be observed that in the results from South Georgia the 



K IV 28 



