1908] Nervous System of the Larva of Corydalis 113 



Nerve C, as described under ganglion /, consists of two 

 branches. 



The nerves of the connectives (Fig. 2, n^c, n.,c, n.f, n/). 

 From the connectives of the thorax there arise four pairs of nerves 

 of which the first two belong to the pro thorax, the third to the 

 mesothorax and the fourth to the metathorax. In their origin 

 from the connectives, these nerves display quite a variation. The 

 first pair may arise from the connectives either in the head or in 

 the prothorax. The two nerves of a pair are not alwa^^s directly 

 opposite but may arise at different levels. 



The nerves of the first pair arising from the connectives {n^c) 

 extend laterad for a short distance receiving branches from the 

 transverse nerve of the sympathetic system. They then turn 

 caudad between the large ventral muscles and terminate in the 

 caudal regions of the prothorax. 



The second pair {n^c) arise from the connectives near the first 

 thoracic ganglion. They extend laterad to the sides of the pro- 

 thoracic segment. 



The third {n.f) pair of nerves originates slightly caudad of 

 the middle from the connectives between ganglia / and //. 

 They extend laterad, one on either side, and give rise to three 

 branches, at the same level, 2-3 millimeters from the base of the 

 main nerve. The first of these branches projects cephalad into 

 the caudal regions of the prothorax; the second extends laterad 

 passing under the large trachea and gives off at this point a slen- 

 der branch which joins the tracheal nerve. As Fig. 2 shows, this 

 tracheal nerve is connected with the transverse nerve of the 

 sympathetic system; the third branch runs caudo-laterad and 

 passes over the large trachea to the sides of the mesothoracic 

 segment. 



The fourth nerve {n^c) originating between the meso- and the 

 metathoracic ganglia, resembles the third and its branches have 

 an analagous distribution and relation to the remainder of the 

 nervous system. 



The Abdominal Ganglia* and Connectives. 



The abdominal ganglia consist of eight small ovoid nerve 

 centers, situated below the alimentary canal and above the large 

 ventral muscles. As a rule each granelion is situated in the 



* The modification of the first and eighth abdominal gangHa will be 

 described separately. 



