54 WALTER K. FISHER, 



part lies under the oesophagus, and the nerve can be seen to join the 

 network of nerves which covers the intestine at this point. 



The other nerve {x) to the oesophagus leaves the ganglion at its 

 uppermost end, and passes directly to the oesophagus, which it follows 

 along the right wall, to the proventriculus. 



From the right pleural ganglion a small nerve (0) departs near 

 the two others already referred to and passes through the visceral 

 loop, whence its course is backward in the dorsal wall of the funnel- 

 shaped mouth of the visceral artery. It then follows the visceral 

 artery backward, lodged in the dorsal wall, and close beside branch 

 c of the right stomatogastric. All these nerves on the visceral artery 

 may finally reach the intestine, but are too small to follow unless 

 lodged in some resistant tissue. 



Two other nerves leave the right pleural ganglion. A dorsal one 

 (Fig. 3 v) innervates the aorta and posterior portion of the pharyngeal 

 pouch. The ventral nerve (v') passes forward along the floor of the 

 pharyngeal pouch which is here thin-walled. 



There are three nerves from the left pleural ganglion which have 

 been found to innervate the viscera, principally the oesophagus (Fig. 41 

 I, m, n). The innermost (I) is the largest. It goes directly upward 

 to the oesophagus and divides into several branches, which pass back- 

 ward along the ventral, dextral, and dorsal walls of the oesophagus, 

 anastomosing freely. These nerves form part of the general supply 

 for stomach and intestine. The next nerve (m) is smaller and usually 

 divides only a few times. Its branches pass backward along the 

 ventral wall of the oesophagus. The third nerve (w) has a similar 

 course. A branch of the nerve m passes to the right and follows the 

 visceral artery along with the other nerves already described (m'). 

 Branches of the nerve I not alone supply the oesophagus, but also 

 that portion of the intestine to which the nerve y' goes. 



The visceral commissure and nerves from its ganglia 

 (Figs. 35 and 39). The visceral commissure as will be seen from the 

 figure is not extensive, and is situated to the right of the pharynx. 

 The upper loop of the "Fig. 8" encircles the aorta. The three 

 ganglia are rather small and are close together, there being little or 

 no commissural connective between them. The left or supra-intestinal 

 ganglion is situated on the left side of the aorta, and in life is 

 covered by the acini of the pharyngeal or posterior salivary glands. 

 As already described the left osphradial nerve arises from this ganglion. 

 On the right side of the aorta, in that portion of the loop arising 



