LEPUS CUNICULUS 305 



noticeably wider than the preceding portions. Its walls are pursed 

 up into a series of marked sacculations, arranged at first in three 

 longitudinal rows, then in two rows, then in one and finally dis- 

 appearing altogether and leaving its wall smooth. This then passes 

 over into the terminal portion of the gut, the rectum, a tube about 

 two and a half feet long, about the same diameter as the small 

 intestine ; it is slightly bent at first, but finally runs straight back- 

 wards through the pelvic cavity to open externally at the anus. 

 Throughout its length it is usually marked by the presence of a 

 series of pill-shaped bodies, the faeces. 



At the junction of the ileum and colon is a large blindly ending 

 tube, the coecum, which is not represented in the frog or dogfish. 

 It is a little longer and much wider than the colon and its greenish 

 coloured, thin walls exhibit about twenty-five turns of a spiral 

 constriction. Proximally it opens into the colon and distally it 

 ends in a narrower thick-walled vermiform appendix, about four 

 inches long,- whose walls are granular in texture and pinkish in 

 colour. Animals confined to a vegetable diet, i.e. herbivores, 

 have a more specialised alimentary canal than carnivorous animals, 

 and we find that they possess either a complicated stomach com- 

 posed of several chambers, or if the stomach be simple as in Lepus 

 there is present a large coecum. 



The digestive glands comprise, in addition to those in 

 the walls of the stomach and intestine, the liver and pancreas. 



The liver is a large brown five-lobed mass lying anterior to the 

 stomach with its front surface curved convexly to fit on to the 

 diaphragm, and its hinder surface hollowed out for the various 

 parts of the stomach. It is attached to the dorsal body wall by 

 a fold of mesentery, and also to the diaphragm by a vertical fold 

 of peritoneum, the suspensory ligament, which also marks the 

 division of the gland into right and left halves. The two median 

 lobes, one on each side of the ligament, are termed the right and 

 left central lobes respectively. Outside the left central lobe and 

 between it and the cardiac end of the stomach lies the left lateral 

 lobe. Externally to the right central lobe is the caudate lobe, which 

 is applied to the anterior surface of the pyloric end of the stomach 

 and postero-dorsally is hollowed to fit over the front end of the 

 right kidney. The remaining lobe, the Spigelian, is shaped so as 

 to fit closely against the median antero-dorsal surface of the stomach. 

 The gall-bladder is a longish thin-walled sac partially embedded 

 in the ventro-median border of the right central lobe, and from it 

 a duct about two inches long passes backwards to open into the 

 duodenum just a short distance beyond the pylorus. From each 

 lobe of the liver comes a hepatic duct to open into this main duct 



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