54 Annals Entomological Society of America [Vol.11, 



coming from the ventral transverse connecting branch, the cau- 

 dal from the lateral tracheal tubes below the ganglion; one pair 

 supplying the middle part of the connectives between the suboes- 

 ophageal and the first thoracic; one pair supplying the first 

 thoracic and one unpaired to the same ganglion ; one pair to each 

 of the remaining thoracic and one pair to each abdominal gang- 

 lion. The last ganglion receiving two branches from the caudal 

 region as well as two large branches from the system of the se\-enth. 



The tracheae of the central nervous system of Corydalis larva 

 seem to be uniformly as outlined above, and the branches which 

 supply the nervous system come directly from large tubes and 

 these in most cases take their origin not far from spiracle openings 

 in the thoracic region and from very near the gills in the abdonii- 

 nal region. 



The larger branches in the ganglia are quite uniform in the 

 distribution of their smaller tracheoles. There was found to be a 

 greater variation in the connective branches in the same individual 

 and in the ganglia of one specimen as compared with an other. 

 The supply to the connectives however, was quite uniformly given 

 by the tracheal systems of the ganglia at either end of the con- 

 nectives. The only variations were the constant ones ; first, in the 

 additional extra supply to the long connectives between the sub- 

 oesophageal and the first thoracic ganglia; second, in the supply 

 to the connectives between the seventh and eighth abdominal 

 ganglia, where the tracheae from the seventh ganglion furnish the 

 connective branches. 



All nerves connected with the ganglia were found to have a 

 good tracheal supply, usually one rather small tracheole which 

 branched many times and here as in the connectives, the branches 

 wound about without anastomosis and without any particular 

 indication of the direction of the nerve fibers, that is transverse 

 as well as longitudinal branches were numerous. 



The branching of the smaller tracheae from the larger was rather 

 irregular and the course and distribution of the finest branches 

 was very complex. Within the ganglia as a rule fewer larger 

 branches were seen. On the surface, and each side of the middle 

 line dense masses of tracheoles outlined the central part of the 

 ganglion. But although there were these two dense tangles one 

 on each side in each ganglion, numerous minute, and some larger 

 branches crossed from one part of the ganglion to an other dis- 

 tant region and mingled w4th the branches from other systems. 



