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ZOOLOGY 



SECT. 



vyaw 



rad. 



Fig. 614.— Triton nodiferus. Interior of the 

 buccal mass, from above, magnified. I. jaw, left 

 jaw : odont. lateral surface of odontophorc ; rad. 

 radula ; r. jaw, right jaw. 



direction ; and, when the cavity of the organ is opened, it is found 



that these correspond to numerous delicate folds which extend 



far inwards, and almost 

 completely block up the 

 lumen. On either side of 

 the crop is a large gland 

 — the salivary gland (Fig. 

 613, I sal. gl, Fig. 617, 

 r. sal. gl.) — partly composed 

 of a compact glandular 

 substance, partly of spongy 

 tissue in which the secre- 

 tion collects. The two 

 salivary glands are unlike 

 in size and shape, that on 

 the left-hand side being 

 much longer than that on 

 the right. Each has a nar- 

 row duct (sal. du.) which 

 runs forwards and inwards 

 to the dorsal aspect of the 



oesophagus, where the two come into close apposition, becoming 



embedded in the wall of the oesophagus, along which they run 



forwards to open into the buccal cavity. 



From the crop leads backwards and to the left a narrow 



cylindrical tube — the 'posterior oesophagus. On this follows 



a stomach (Fig. 



611,stom.) which 



is in the form of 



a U-shaped tube 



partly embedded 



in the substance 



of the digestive 



gland or " liver," 



the hepatic ducts 



from which open 



into it. The tu- 

 bular stomach is 



followed by a 



somewhat nar- 

 rower tube — the 



intestine (Fig. 



613, int.). This 



enters the cavity 



of the nephridium, round the interior of which it bends; and, 



leaving it at its right-hand side, runs forwards in a straight 



course as the rectum (red.), embedded in the glandular wall of the 



rad hocL.cccv 



jcvw 



"bocL.ccuv 



CU.7'1 



ra.ciL.sac 



Fio. 615.— Triton nodiferus. Diagrammatic longitudinal ver- 

 tical section of buccal cavity, bod. car. body-cavity ; cart, car- 

 tilage of odontophore ; jaw, right jaw ; of*, oesophagus ; rad. 

 radula ; rad. sac. radula sac. 



