It is at times sacculated, but its chief interest is that, as Lebedinsky 1 has shown, the tip of the caecum in embryonic life opens to the exterior as the blastopore.
The mouth opens at the tip of the retractile proboscis; it leads into a short thin-walled tube which opens into an oval muscular gizzard lined with a thick cuticle; at the posterior end of this are some minute glands and then follows a large stomach slightly sacculated in each segment, this tapers through the rectum to the terminal anus.
All rodents, with the sole exception of the dormice, have a caecum, often of great length and sacculated,, as in hares, the water-rat and porcupines; and the long colon in some, as the hamster and water-rat, is spirally twisted upon itself near the commencement.
The intestinal canal is long, and has, in addition to the ordinary short, but capacious and sacculated caecum at the commencement of the colon, lower down, a pair of large, conical, pointed caeca.
Long and nearly a foot in diameter; its walls are sacculated, especially near the base, having four longitudinal muscular bands; and its capacity is about twice that of the stomach.