Transverse Nerves 



47 



explanation of their special 

 function, but notes that they 

 communicate with branches 

 of the ventral cord, and 

 send branches towards the 

 spiracles. Newport calls 

 them transverse nerves from 

 the direction of their prin- 

 cipal branches, and also re- 

 spiratory nerves from their 

 special distribution to the 

 breathing organs. Blan- 

 chard and Leydig^ identify 

 them with the sympathetic 

 nervous system of Verte- 

 brates. Since there is no 

 experimental proof of their 

 function, we adopt the neu- 

 tral name of transverse 

 ney'ves'-^. Their regular de- 

 velopment throughout the 

 body of the Chironomus- 

 larva, which (in our species) 

 has no open spiracles, and 



' (1864 b), p. 203. 



- H. Landois, in liis juvenile 

 thesis, Be systemate nervorum trans- 

 versorum (Greifswald, 1863), tliinks 

 that transverse nei'ves are parti cu- 

 hirly well developed in insects which 

 have in the winged state a mobile 

 abdomen (p. 24). 



Fio. 38. — Stomato-gastric nerves of larva, aes, oesophagus, crt, cardiac chamber 

 of stomach, rf.v, dorsal vessel. 6r, brain, ^/".(y, frontal ganglion. ?'.«, recurrent 

 nerve, w*, nerve passing from brain to frontal ganglion (Newport's fourth nerve j. 

 77i', point of division of recurrent nerve. <?•, trachea, jj.jf, paired ganglia. dv.7i, 

 nerve to dorsal vessel, dv.g, ganglia of dorsal vessel, gn, gastric nerve, to cardiac 

 chamber. The course of the recurrent nerve beneath the dorsal vessel is dotted. 



