Literary Notices. Ixiii 



this the supraa'sophagal ganglion forms about one half and rises above 

 the cephalic part of the thoracic ganglion as a strongly prominent dor- 

 sally flattened elevation of nearly circular outline which cephalad, where 

 it almost adjoins the pharynx, falls off abruptly to the oesophagus. The 

 lower thoracic ganglion forms likewise a rather thick mass and is ex- 

 panded posteriorly and assumes a somewhat radial form by reason of the 

 nerves issuing from it. 



The whole ganglionic mass is clothed with fine neurolemma upon 

 which there occasionally appear elongated nuclei and which extends out 

 upon the nerves. Beneath the neurolemma is a closely packed layer of 

 nerve cells which have vague contours and roundish, deeply staining nu- 

 clei of .006 mm. diameter; these cells surround the central mass on all 

 sides, but are thinnest on the dorsal surface of the thoracic ganglion. 

 Nerve cells of greater dimensions were not observed in Chernes and noth- 

 ing can be said respecting their processes. This layer is thickest on the 

 surface of the supra-cesophagal ganglion as well as on the ventral surface 

 of the thoracic ganglion. 



The central mass in the region of the thoracic ganglion is divided 

 into 6 pairs of elongated granulo-fibrous accumulations from which spring 

 the nerves to the five larger extremities and the sixth posterior nerve pair 

 and which are surrounded by a connective sheath which seems to origin- 

 ate from the connective tissue about the oesophagus. ... In 

 longitudinal sections there appears in the fore-part of the supraoesophagal 

 ganglion a protuberance of the inner substance of both sides perhaps 

 forming the ganglion of the mandiblary palp. . . . No ros- 

 tral ganglion, such as found by Schimkewitsch in Aranea, was found in 

 Chernes. 



TwQ strong bifurcating nerves spring from the supraresophagal gan- 

 glia which can be followed to the vicinity of the mandiblary palp and 

 probably innervate them. Between these an azygous nerve arises and 

 passes over the pharynx. . . At a higher level two small 



nerves spring from the cephalic part of the brain and are regarded as 

 atrophied optic nerves, although eyes are absent in Chernes. Two very 

 large maxillary nerves arise from the thoracic ganglia and give off a fine 

 mesal branch which at once subdivides. The nerves of the extremities 

 follow and finally, at a higher level, a^ strong pair which divides to send 

 tile mesal branch to the genitalia and the lateral to the liver sac," 



