ORCELLA. 377 



process. In this respect, therefore, it is comparable to the paunch of ruminants, or it 

 may be, to the gizzard of hhcls. Superficially, at e, there is relatively a considerable 

 thickness of a somewhat coriaceous or horny epithelial layer, and which follows the 

 sinuosities of the ridges and furrows. The epithelium is chiefly squamous and in 

 horizontal compressed layers on the free surface, but, here and there, and deeply, 

 groups of cylindrical epithelial cells are less or more aggregated together. These 

 somewhat Avavy horizontal layers, without any very marked line of demarcation, abut 

 against and seem to constitute a series of vertical papillae, similar to those of the skin, 

 but their general appearance simulates the true gastric foUicules of the succeeding 

 stomach cavities. The series of columnar tubes {c. g.) descend in nearly parallel 

 straight lines to the subjacent areolar tissue ; their inferior differing from their upper 

 extremities by terminating in clear and distinct, obtusely tapering or occasionally 

 bulbous ends. These cylindroid columns are evidently of a solid consistence, and 

 composed of epithelial cells varying in figure according as they are more loosely 

 or more densely packed. The papillary interspaces are less than half the thickness 

 of the columns and much more transparent ; they have a somewhat fibroid character 

 from the upright closely pressed position of elongate cells. Inferiorly this lineo- 

 cellular character passes into the more distinct fibro-cellular tissue beneath. Here 

 and there, muscular bands or cut ends of muscular fibres form an imperfect layer in 

 the areolar tissue ; the latter is wider-meshed and more fibrous below, and many 

 minute blood-vessels {v.) traverse it in diverse directions. 



A similar vertical section of the wall of the second stomach as seen somewhat 

 more highly magnified (fig. 15) reveals the presence of a comparatively very thin 

 and scarcely appreciable layer of free epithelium. The smoothish surface is every- 

 where perforated by orifices, the mouths of capacious gastric glands. These latter 

 are long and tubular, mostly single, and straightish throughout or with wrinkled 

 walls, although some either obscurely or more definitely point to saccular branching 

 m their lower segments. The tubules are filled with the so-called peptic cells 

 of the ordinary character. The sub-mucous, fibro-cellular and areolar tissue, with 

 occasionally muscular fibrillse, agrees to a certain extent with that of the first 

 cavity of the stomach, but it differs in being more copiously supplied with blood- 

 vessels, which are of great calibre and exceedingly thick- walled, and more shall be 

 said of them presently. Indeed, as fig. 5, v, shows, their interior is reduced to a 

 small hollow centre surrounded by a circular fibrous waU far exceeding the apparent 

 necessities of the narrowed channel. 



The third cavity of the stomach, and wherein possibly digestion is most actively 

 carried on, has abundance of gastric glands, as in the preceding chamber, and, like it, 

 many blood-vessels ramify within its musculo-serous coats. 



Vascular chamiels of the stomach. —J] ndiQi^ this head it is desirable to call 

 attention to their general distribution along with certain other glandular structures 

 in connection with them. In Professor Turner's account of the great Pinner Whale 

 stranded at Longniddry,^ he has given some interesting observations on a remarkable 



1 Trans. Roy. Soc. Edinb. 1870, vol xxvi. pp. 231, &c. 



z2 



