fi k'l.iry 

 . 



E T O I 



Pongue. 



3yllct. 



spound 



i.ich. 

 . I E 



CXXI1I. 

 f-7. 





for ITbJpd from that ,- ' r \V. 



" $<-ou--.!>\ , iii the ' \lein n\ nf the 



: I 

 the tlcM-riptiou of the i 



of whalebone aft> netftr the tin... it than the snout, 

 and they become gradually shorter before and behind 

 thu point. They are curved in two direction*, HHP 

 longitudinally from the sides to the centre < 

 * mouth, and transversely. The whalebone is covdlMr 

 below by the under or basilar lips, which, when the 

 mouth is shut, overlap the upper part in a squamous 

 ' manner. ' ^rf* ' 



The plates of n'/inl<-Lonc are of a black colour, 

 mottled with shades of a lighter hue ; but they often 

 appear of a greyish cast, from the thin skin with 

 which they are invested, and which is of this latter 

 colour. 



The tongue of these animals is most remarkable 

 for its size, being comparatively large in all the spe- 

 cies, but particularly so in the balance. In sub- 

 stance it varies in the different tribes, being of a firm 

 texture in the porpesse, grampus, and other dolphins, 

 but soft and spongy in the proper whales. In these 

 latter the tongue, both in size and substance, has 

 been compared to a feather bed. It is composed 

 partly of muscle, and partly of fat, with which it so 

 abounds in the balcena, as often to produce several 

 tons of oil. In some species it is covered with a fine 

 smooth skin, while in others it is rendered rough on 

 the surface by numerous papillary protuberances. It 

 is usually pointed at the anterior, or antinial extre- 

 mity, and serrated on the edges. It projects most in 

 those species that are furnished with teeth." 



The asophagitSj or gullet of cetaceous animals, has, 

 with respect to its general structure, been sufficiently 

 described under Comparative ANATOMY. Its dia- 

 meter differs considerably in different species. In 

 the Greenland whale, the largest of the class, it is 

 so small, as with difficulty to admit the passage of a 

 hen's egg, while in the piked whale it has been ob- 

 served 3-^ inches wide, and in some other species it is 

 probably much wider. It is proportionally widest 

 in the dolphin tribe, especially in the dolphin and the 

 porpesse. 



The cetacea resemble the ruminating quadrupeds 

 in the complicated structure of their stomach. This 

 organ consists of four, and sometimes five distinct 

 cavities, connected with each other in a manner some- 

 what different from those of the ruminating quadru- 

 peds. In the dolphin and porpesse, (which we may 

 quote as among the most familiar and procurable ex- 

 amples, ) the first stomach is the irost extensive, and 

 of an oval form, having on its central surface thick 

 circumvolutions, and elevated ridges round the ori 

 fice, by which it communicates with the second sto- 

 mach ; thus preventing the return of the food from 

 the latter into the former. The second stomach* is 

 also oval, and rather less than the first ; marked in- 

 ternally with longitudinal rounded channels, united 

 by others that cross them transversely, like the fin- 

 gers of the two hands when joined together. Be- 

 tween the second and the first stomach, and between 

 the former and the third, there is a short canal, 

 which forms a narrow passage from the one to the 

 other. The third stomach is lengthened out like an 

 intestine, and curved in the form of an w ; its sides 

 are much finer than thoe of the two preceding, and 

 VOL. v. PART II. 



O C V ^ 



its central <vB|l 



without wrinkles. 

 IB contracted by a 

 membranes. 1 he 



mil tur 



s 



Hy, and its v * 



-pic tructuU';;!; 



small externally, 



f 



M0tat 



.t! 

 ,ort of jxttl, rurnie 



JMtth titomach 



in capacity; it is short ati 

 struct a re appear* the same 

 Its outlet is marked by a 

 ^h^rienition or valvular fold. 



The rest of the intestinal canal 

 and the folds of its central mrmbran-- 

 tinct and protuberant, so as to render the 

 vity of a cellular structure, the folds ac 

 many valves that impel* t|p*con|entB for 1 

 prevent their return. The distinction into 

 great intestines is also very evident. The ro< 

 cral part of the intestines, or rectum, appears con- 

 tracted, is glandular, and covered by a soft cuticle, 

 and its termination in the anus is very small. 



The food of cetaceous animals is different, accord- 

 ing as they are furnished with teeth, or destitute of Cacea. 

 these' organs. The dolphin tribe live on various spe- 

 cies of fish, especially cod fish, Jtat/ifft, and tlogfah. 

 Some of the more raveuous of this tnbe, as the 

 grampus, will prey on others of their own tribe, and 

 will even attack the larger whales, and suck their 

 blood. Those of the physeter tribe, or the sperma- 

 ceti whales, are said to feed on the smaller of the 

 dolphin tribe, and on seals ; andthe/arge spermaceti 

 whale is said to pursue with avidity the shark, which 

 is supposed to constitute a great part of his natural 

 food. The balance and the narwhals live chiefly on 

 various species of mollusca, such as actinia and me- 

 dusa, though some of them certainly devour large 

 quantities of herrings, and other smaller fishes. 

 These they swallow whole. 



SECT. IV. Circulation. 



There is little remarkable in the conformation of Heart and 

 the circulating system of the cetacea, which differ! 

 from that of MAMMALIA in few particulars. Theirhcart 

 is proportionally larger and flatter ; their vena ca 

 larger ; and the arteriee in many parts more tortuou 

 and more divided. 



The quantity of blood that circulates within the 

 vessels or some of these animals is prodigious. It is 

 calculated, that in some of the larger balxnae, the 

 diameter of the aorta often exceeds 13 inches, and 

 that the heart in these species is capable of project- 

 ing from its ventricles ten or fifteen gallons of blood 

 during one pulsation. The blood of cetacea scarce- 

 ly differs in its nature and appearance from that of 

 quadrupeds. Hunter, in Phil. Trans, vol. Ixxvii. 

 p. 4I. 



It has been supposed by some naturalists, that the Oval hole 

 passage which is usually found in .the Jacttis of n>an not ;oun-~ 

 nnd MAMMALIA, immediately connecting the ventn- P C11 - 

 cles of the heart, and which has bepn called by ana- 

 tomists foramen on/ VATOMY, vol. i. p.809.). 



coi.tinues open after birth in the cetacea, and other 

 animals that pass much of their lives under water ; 

 but this opinion, at least with respect to the ccta- A 

 cea, is erroneous. Indeed, if we consider the short 

 time during which these animals can keep entirely 

 below the surface of thewatei, (which seldom ex- 

 ceeds twenty minutes,) it must be evident, that their 

 necessity for frequent respiration it nearly equal to 

 4R 



