452 



ANATOMY OF VERTEBRATES. 



part in the Manis. 1 In all Sloths the duodenum is loosely sus- 

 pended, and is continued without constriction of mesentery into 

 the rest of the small intestines, which is disposed in many short 

 convolutions, and enters a short and straight colon, without a 

 caecum. The anus is not distinct from the vulva. 



§ 333. Alimentary canal of Cetacea. — The first peculiarity to be 

 noted in this order is the small area of the gullet in the largest 



species, especially in the 

 great Whale-bone Whale 

 (Balcena mysticetus): its 

 lining membrane is here 

 disposed in longitudinal 

 folds which close the area 

 of the tube in the con- 

 tracted state : they are 

 coated by a thick irregu- 

 larly rugous epithelium, 

 and are connected with 

 the strong muscular coat 

 by a deep layer of elastic 

 cellular substance. The 

 stomach is complex, di- 

 vided into several cavi- 

 ties, in all true Cetacea. 

 In the Porpoise (Phoccena 

 communis), fig. 355, the 

 first cavity is continued 

 in the same line with the 

 oesophagus, having the 

 same structure, and not 

 being divided from it by 

 any sensible constriction ; 

 its commencement is in- 

 dicated by the orifice 

 leading into the second 



Stomach, liver, and spleens, of the Porpoise, cxliv". (From stomach, beyond which 

 a drawing by R. O. the prep, dry, is iu Mus. Coll. Chir.) ^.^ ^ . g C()ntInued fc 



the form of a dilated ovate cavity, ib. a, a. It is lined with a 

 cuticle, or thick laminated epithelium, and its inner surface is 



1 The fig. 354 has been taken by the writer of ex", from cxxn'. vol. xiii. pi. in., 

 fig. 2. The foregoing description is from dissection of the specimen of Cholvpus didac- 

 tylus which died at the London Zoological Gardens, in 1851, and in which the arteries 

 were previously injected. See cxi.vn". p. 167, No. 553 c. 



