206 



ment of the organs of special sense in the latter form. The 

 distribution of the nerves to the special sense-organs, howevei', 

 has not been followed out, save that, in some of my sketches 

 of the wingless forms, I find a pair of nerves given off from the 

 anterior end of the hemispheres, which I have no doubt sup- 

 plies the eyes, and that another [)air arises from the ventral 

 aspect of the same hemispheres, and probably makes its way to 

 the antennae. In the winged forms, the hemispheres lie in 

 such close approximation to these organs that the nerves will 

 certainly be found to be vei'y short. 



As may be seen from the accompanying figure, the 

 oesophagus ascends in the space bounded by the arcus superior 

 behind, and by the brain commissure in front. J^. L. Mark. 



Cambridge, Dec. 24, 1878. 



Note. — After the preceding article was in type my atten- 

 tion was directed to an article by Targioni-Tozzetti ^ through a 

 review of the same by P. Mayer in Hofmann u. Schwalbe's 

 Jahresberichte ueber die Fortschritte der Anatomic und Physi- 

 ologie. Bd. 6, Abth. 2 : Entwickelungsgeschichte ; Anatomic 

 der wirbellosen Thiere. p. 185. 187b. 



Inasmuch as the article alluded to contains a short statement 

 with regard to the nervous system in a nearly related species of 

 the same genus, I will take advantage of tiie opportunity here 

 afforded to give its substance. 



The author says (p. 237) : " The nervous system is com- 

 posed, as far as regards the suboesophageal part, of two gang- 

 lia ; it is not possible to separate from the surrounding parts 

 the superoesophageal ganglion so as to define it with accuracy. 

 Of the two ganglia beneath the oesophagus, the anterior is the 

 smaller, it is heart-shaped and joined by means of two thick 

 and short divaricating commissures to the posterior ganglion, 

 which is larger and pyriform. The latter gives rise to lateral" 

 nerves, and ends with a long, thick cord, which, having fur- 

 nished some branches in its course, is divided into other 

 branches and there terminates." 



1 Somnifu'io di iiuove osservazioni siilla Fillosserfi del Leccioe della Querce. — {Phijl- 

 loxerajlorenlina, Ph. signorcti) Targ. Bull. Soc, Knt. Italiaiia, v. 0, p. 236-239. 1877. 



