[duporte] LARVA OF SPHIDA OBLIQUA WALKER 243 



ganglion at the base' of the optic nerve. From this point it runs 

 obliquely forward passing between the mandibular muscles. It 

 bifurcates and the two branches run along the wall of the head dorsal 

 to the ocelli, innervating the setae of the epicranium. The latter 

 portion of this nerve has the appearance of a nerve of the brain, and 

 is described as such by Newport, but it undoubtedly belongs to the 

 lateral sympathetic system. 



Nerve r, which arises from the lateral border of the ganglion, 

 runs first ventrally and then bends forward. Near its base it sends 

 three very minute branches back to a branch of the tracheal system. 

 Near branch a of the maxillary nerve it enlarges into a ganglion which 

 receives a nerve from this branch (fig. 4). It terminates in branch 

 dZ of the maxillary nerve near the base of the maxilla. 



Nerve s arises between the origin of p and q and runs inward to 

 the oesophagus where it branches, sending nerves to the oesophageal 

 muscles. 



Nerve t originates behind nerve q, travels inward and divides 

 into three branches. The proximal branch, x, is given off near the 

 lateral border of the oesophagus and goes to the oesophageal muscles. 

 Branch y innervates the dorsal vessel, and z fuses with the recurrent 

 nerve, thus connecting the lateral with the vagus sympathetic system. 



Nerve u is given off near the base of p and runs in a lateral direction 

 terminating near the origin of the labral muscles. 



From the posterior side of the second ganglion two minute nerves 

 are given off. These terminate in a gland which has the appearance 

 of the salivary gland but which I have not succeeded in tracing 

 thoroughly. 



3. THE SUPERADDED OR VENTRAL SYMPATHETIC 

 SYSTEM. 



In the ventral sympathetic system there are, typically, a median 

 nerve originating from each pair of connectives (except the first) in 

 the ventral chain, and a pair of transverse nerves given off from each 

 median nerve. The transverse nerves in each segment are closely 

 connected with the central nervous system. 



The Median Nerves. (Figs. 1 and 2, m.n.) These nerves 

 arise from the connectives at the point where they separate from each 

 other. They run back between the connectives, terminating in the 

 transverse nerves. 



The Transverse Nerves. (Figs. 1 and 2, tr. n.) In the first 

 thoracic segment the transverse nerves do not arise from a median 

 nerve. Instead, they originate anterior to the second thoracic gang- 



