Fig. 387.—Lepus cuniculus, rabbit. Ileo-colic junction with saccus lymphaticus. Cæcum and proximal segment of colon opened to show spiral mucous fold in interior. (Columbia University Museum, No. 1587.)   Fig. 388.—Lepus cuniculus, rabbit. Cæcum and appendix inverted to show spiral fold and structure of mucosa. (Columbia University Museum, No. 1588.)

The coils of the proximal colon encountered in many rodents are well seen in Dasyprocta agouti, the agouti (Figs. 389 and 390), which animal also illustrates a type of cæcum found in several members of the order. The pouch here is large, sacculated, uncinate, without reduction of the terminal portion.

Fig. 389.—Dasyprocta agouti, agouti. Ileo-colic junction, cæcum, and colon. (Columbia University Museum, No. 24/1576.)

Fig. 390.—Dasyprocta agouti, agouti. Ileo-colic junction, cæcum, and colon. (Drawing based on preparation shown in Fig. 388.)

Fig. 391.—Lagomys pusillus. Ileo-colic junction, cæcum, and colon. (After Pallas, from Oppel, “Lehrbuch d. Vergl. mikrosk. Anat. d. Wirbelthiere,” II., Jena, 1897, p. 577, [Fig. 314].)

Fig. 392.—Arvicola pennsylvanicus, field mouse. Ali­men­tary canal. (Columbia University Museum, No. 815.)   Fig. 393.—Mus decumanus, white rat. Ileo-colic junction, cæcum, and colon. (Columbia University Museum, No. 1574.)

The relatively enormous size of the cæcum in the Muridæ is shown in Fig. 392, representing the entire visceral tract of Arvicola pennsylvanicus, the meadow mouse. The pouch in these animals is large, smooth and of uniform caliber (Fig. 393).