APPENDIX 



however, it is impossible to present the subject except in 

 semi-technical language. 



The bones of the Cetacea are comparatively light and 

 fragile, the hard, shell-like exterior being thin and the in- 

 terior filled with spongy "cancellous tissue" which is con- 

 siderably impregnated with oil. In structure they are exactly 

 opposite to those of the Sirenia (the aquatic mammalian 

 order including the sea cows, or manatees, and the dugongs), 

 which have very heavy solid bones of almost flinty hard- 

 ness. Cetacean bones are easily affected by weather, and if 

 exposed to the sun, rain and wind for a comparatively short 

 time the hard exterior becomes white and chalk-like. 



The whale's skeleton is highly modified in adaptation to 

 an aquatic existence and is very distinctive of the cetacean 

 order. In a general view it is seen to be greatly elongated, 

 the skull is pointed, the fore-limbs are short and flat and the 

 hind-limbs are represented by nodules of bone; all these ac- 

 company a fish-like body which offers little resistance to its 

 passage through the water. 



The skull is perhaps more greatly modified than any 

 other portion of the skeleton, and if a trained anatomist who 

 had not studied the Cetacea were to examine a whale's skull, 

 he would probably be at a loss to identify correctly its parts. 

 The brain case is small and rounded, the eyes are situated 

 far back and the facial portion greatly elongated. The back 

 of the brain case is formed by an extraordinarily developed 

 supra-occipital bone which extends forward and upward to 

 meet the frontal, entirely excluding the parietals from the 

 summit of the skull. The nostrals have rotated backward 

 and upward and are almost vertical instead of horizontal as 

 in other mammals ; thus the nasal bones are greatly reduced 

 in size. 



The skull of a toothed whale in general appearance is 

 quite unlike that of a whalebone whale; the nasals are very 

 small, and the maxillae, premaxillae" and f rentals meet above 

 the nostrils to form a bony ridge which is sometimes de- 

 veloped into an extraordinary crest. In some cases the crest 



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