246 



NATURAL HISTORY. 



oiit. The gullet is narrow in some, and wider in others, but the stomach in all is peculiar, and composed 

 of three or more chambers with narrow passages between; in this respect corresponding to that of Sheep 

 and cattle. The intestines are long, glandular, and full of little pouches. There is no gall-bladder. The 

 brain is of considerable calibre, globular, and remarkably convoluted. The 

 heart is distinguished only for great size, and the blood vessels are exceedingly 

 capacious and numerous. But what is remarkable in the vascular system is 

 a great mass composed of enormous numbers of minute tubes, forming a so- 

 called rete mirabile, like that formerly described in the Lemurs. It is situated 

 within the body along the inside of the spine. This, in the Whales, has been 

 supposed to be a respiratory provision to enable them to remain long sub- 

 merged ; but I have shown elsewhere that its connection with the glands of 

 the lymphatic system may render it functionally subservient to nutrition and 

 purification of the blood. The lungs are large, but the most extraordinary 

 features are the larynx and nasal passages. The nostrils, often a single 

 crescentic aperture, open right on the top of the head, except in 

 the Sperm Whale, and not in front as in all other Mammalia. In 

 some thei % e are small pouches near the orifice or blowhole of 

 .c uncertain use. In front of the larynx of man we all know 



there is an elastic lid, the epiglottis, 

 which folds over and protects the i 

 passage as food is swallowed. The side 

 cartilages constitute the walls of the 

 organ of voice, and protect the vocal 

 cords. Now, in the comparatively 

 *53^:j mm voiceless Whale the cartilages including 



the epiglottis form a long rigid cylin- 



INTERIO* VIEW OF LARYNX OF RISSO'S GRAMPUS. (After Murie.) ^^ ^^ ^^ g ^.^ ^ ^ 



Ep, epiglottis;. vc, vocal cord; s, sac; c, cartilage; gl, gland; tr, trachea. The arrows ,1 i /. ,1 i , 



show direction of air-currents In ingress and egress. passage at tile DaCK Ol tile palate in 



continuity with the blowhole. It is 



there held in place by a muscular ring. With the larynx thus retained bolt upright, and the 

 blowhole meanwhile being compressed or closed, the Cetacean is enabled to swallow food under 

 water without the latter entering the lungs. Respiration, " blowing " or " spouting," takes place 

 at intervals as the animal reaches the surface, and the volume of air thrown up along with sur- 

 rounding moisture and condensed vapour in some rises in a great jet. The flesh of the body 



SKELETON OF SPERM WHALE. (After Flower.) 

 8, Spermaceti Cavity ; n, Nasal Passage, in dotted line ; &, Blowhole. 



terminates in long cords of tendon running to the tip of the tail. These tendons, like a te]egraphic 

 cable, bound together in the smallest compass, are moved by the enormous fleshy masses of the 

 body, and thus their vast force is conveyed to the caudal appendage, whose great power as a pro- 

 pelling agent (and even a destructive one) enables the Whales to be truly roamers of the sea. Save 

 the tail and flippers, the body is covered by a dense layer of fat, the blubber. In the skeleton the 

 neck-bones are often soldered into one or two separate pieces, rigidity being needful in front, while the 



