[Illustration: FIG. 206.--Alimentary tract of _Echelus conger_, Conger eel. Stomach, mid- and end-gut, liver, and spleen. (Columbia University Museum, No. 1430.)] [Illustration: FIG. 207.--Stomach, duodenum, and pyloric caeca of _Lophius piscatorius_, angler. (Columbia University Museum, No. 1824.)] Fig. 208 shows the stomach and the beginning of the midgut with four pyloric caeca in _Pleuronectes maculatus_, and Fig. 209 the same parts of this animal in section. [Illustration: FIG. 208.--_Pleuronectes maculatus_, window-pane. Stomach and mid-gut with pyloric caeca and hepatic duct. (Columbia University Museum, No. 1432.)] [Illustration: FIG. 209.--_Pleuronectes maculatus_, window-pane. Stomach and mid-gut with pyloric caeca, in section. (Columbia University Museum, No. 1433.)] [Illustration: FIG. 210.--_Paralichthys dentatus_, summer flounder. Stomach and mid-gut with pyloric caeca and liver. (Columbia University Museum, No. 1431.)] Fig. 210 shows the stomach and midgut of _Paralichthys dentatus_, the summer flounder, with three well-developed conical pyloric caeca. On the other hand in some forms the number of pyloric appendices is enormously increased, while their caliber diminishes. Thus 191 caecal appendages are found surrounding the beginning of the midgut in _Scomber scomber_. A well-marked example of prolific development of the pyloric appendages is furnished by the common cod, _Gadus callarias_ (Fig. 211). The appendices are in the natural condition bound together by connective tissue and blood vessels, so as to form a compact organ, resembling a gland (Fig. 211, A), and a similar arrangement is found in _Thynnus vulgaris_ and _alalonga_, _Pelamys_ and _Accipenser_ (Fig. 212). [Illustration: FIG. 211.--Pyloric caeca of _Gadus callarias_, codfish. (Columbia University Museum, No. 1825.) _A._ Bound together by connective tissue and blood-vessels. _B._ Dissected to show confluence of caeca to form a smaller number of terminal tubes of larger calibre entering the intestine.] [Illustration: FIG. 212.--Alimentary canal of _Accipenser sturio_, sturgeon. Numerous pyloric caeca are bound together to form a gland-like organ. (Columbia University Museum, Nos. 1826, 1827, and 1828.) In the smaller upper figure on the left the stomach, mid-gut, and pyloric caeca are seen in section, showing the lumen of the latter and their openings into the mid-gut. The lower left-hand figure shows the mid- and end-gut in section, the latter provided with a spiral mucous valve.]