iQoS] Nervous System of the Larva of Corydalis 117 



shown in Fig. 10, passing through the lateral Ijorders of the seminal 

 vesicle. 



The intestinal nerve* (Figs. 9 and 10, in. n). The intes- 

 tinal nerves consist of a pair of long, thread-like nerves, which 

 arise from the proximal ends of nerve c of the terminal ganglion. 

 They extend cephalad to the second abdominal segment, where 

 they are attached to the sides of the small intestine, shortly caudal 

 of the origin of the Malpighian tubes. 



Each proximal portion of these nerves gives rise to five 

 caudad-projecting branches, four of which innervate the hind 

 intestine. The first branch arises from the very base of the intes- 

 tinal nerve and lies dorsad of nerve c. It divides into three sub- 

 branches before reaching the hind intestine. Branches 2, j, 

 and 4 do not ramify until reaching the intestine. Branch 5 is 

 comparatively small and, unlike the four previous ones, does not 

 reach the intestine, but is attached to a mass of adipose tissue {ad) . 



The intestinal nerves represent the first or basal branch of the 

 lateral nerve, but in distribution they dift'er radically from that 

 of this branch in preceding segments. It is probable that the 

 suppression of the respiratory nerve, originally occurring between 

 the ganglia represented, and the in-pushing of the proctodaeum 

 are sufficient to account for these modifications, great as they 

 appear. 



THE SYMPATHETIC NERVOUS SYSTEM. 



The sympathetic system is divided into the upper sympa- 

 thetic SYSTEM, lying above the alimentary canal, and the 

 LOWER sympathetic SYSTEM, lying below^ it. 



The nerves and ganglia of this system are very minute and 

 constitute a supplementary system intimately connected with 

 the central system. Most of the nerves are susceptible to methy- 

 lene-blue and can best be studied in specimens prepared with this 

 stain. 



The Upper Sympathetic System is confined to the anterior 

 dorsal portion of the alimentary canal and most particularly to 

 the pharynx and oesophagus within the head. It can be divided 

 into an unpaired median and a paired lateral system. 



The Unpaired Median, Stomogastric, or, as it is more gen- 

 erally termed, the Vagus System, consists of the following parts: 



* Comstock & Kellogg, '04, p. 49. 



