68 



WHALES 



Figure jo. Right view of 

 right pelvic bone of Basilo- 

 saurus cetoides [Owen] 

 Note the socket and the fora- 

 men which are also found in 

 the pelvis of terrestrial mam- 

 mals. {Kellogg, 1936.) 



in ordinary mammals, and therefore to coincide with the point of appHca- 

 tion of the upward force. Hence the whale will float almost horizontally. 



And that is in fact what we observe. Whenever whales come up slowly 

 to breathe, they emerge almost parallel to the water surface (Figs. 32 and 

 51), in a way strongly reminiscent of submarines. While the top of the 

 head and the back as far as the dorsal fin can be seen clearly, the tip of 

 the snout itself always remains submerged. This is also the attitude in 

 which whales and dolphins often doze at the surface. In the great 

 Marineland Seaquarium in Florida, which we shall discuss later at some 

 length, McBride and Hebb observed female Bottlenose Dolphins dozing 

 so that only the blowhole appeared above the surface. Oddly enough, 

 the males, which also doze almost horizontally, do so some 1 2 inches below 

 the surface and come up now and then to breathe in the same way as the 

 larger whales. 



Further experimental data on this subject are still needed, but if we 

 take into account all the available evidence, it seems clear that, from 

 hydrostatic considerations alone, the whale's nostrils ought to lie right on 

 top of the head and behind the tip of the snout - and that is precisely 

 where they are found in all living Cetaceans, with the exception of the 

 Sperm Whale where they lie a little to the left and near the tip of the head 

 (Fig. 33). This is probably due to the fact that the Sperm Whale's gigantic 

 head holds the spermaceti case, an almost rectangular cavity in its upper 

 surface. This enormous 'case' is made up of connective tissue, with enor- 

 mous quantities of fat cells containing spermaceti. Spermaceti is not a 

 true oil, but a glistening wax-like substance which separates out on cooling. 

 Its low specific gravity probably causes the anterior part of the head to 

 break surface first. 



If we make a longitudinal section through the head of a Sperm Whale, 

 we shall find many unsuspected phenomena. That part of the nasal 

 passage which lies inside the skull, and which is therefore enclosed in bone, 

 has the same location as in all other Cetaceans, viz. posterior to the snout. 

 From the skull, however, two long canals run through the spermaceti 



