212 INTRODUCTION. 



The small intestine comes off from the stomach at a 

 very acute angle, and into the latter two hepatic ducts 

 empty. It is pretty uniformly cylindrical, and forms, as 

 in slugs, a single convolution or a sigmoid curve, among 

 the lobes of the liver, and penetrates to the pulmonary 

 cavity at its right posterior angle. The rectum, in all 

 the testaceous genera, corresponds in length to the pul- 

 monary cavity, the right side of which it occupies to the 

 pulmonary orifice, at the outer border of which it ter- 

 minates by the anal aperture. It is cylindrical, usually 

 wider than the small intestine, and is frequently some- 

 what sacculated. Upon the outer side of the rectum, 

 running its whole length, is a band of muscular fibres, 

 the object of which is, apparently, the retraction of the 

 collar, the shortening of the rectum, and the expulsion 

 of its contents. 



The salivary glands are generally elongated, oval, with 

 lobed edges. They are usually united together and 

 situated on the oesophagus, or commencement of the sto- 

 mach. When the oesophagus is narroAV they surround 

 it ; when dilated, they occupy one-half or two-thirds of 

 its surface. The salivary ducts are long and large. 



The liver is four lobed, three of which lobes are ante- 

 rior or inferior, and the fourth posterior or superior. The 

 fourth lobe, conjoined with the testicle, forms the very 

 summit of the turbinated mass. The ducts from the 

 anterior ^obes converge to form a single trunk, which, 

 with that from the posterior lobe, open into the junction, 

 or angle, of the cul-de-sac of the stomach with the intes- 

 tine. 



