1912] Anatomy of Tomato-worm Larva 261 
Median and Transverse Nerves.—The median nerve (m) 
arises from the mid-dorsal area of the double ganglion. It is 
very short. On teasing apart the two ganglia, the median nerve 
remains attached to the caudal end of the seventh abdominal 
segment. It immediately gives rise to its pair of transverse 
nerves (¢. .), which extend caudo-laterad into the eighth 
abdominal segment more or less parallel to and laterad of the 
pair of lateral nerves. However, no plexus exists between the 
transverse and lateral nerves of this ganglion, as was noted in 
the other segments. 
THORACIC GANGLIA (Fig, 17, > le and 7. 29 Fig: 16, 
T. 3g).—The thoracic ganglia are three in number, the meso- 
thoracic and metathoracic ganglia are similar in form. 
Mesothoracic and Metathoracic Ganglia (T. 2g and T. 3¢g).— 
The mesothoracic and metathoracic ganglia are slightly larger 
than the abdominal ganglia and are not as far apart. Extending 
from the caudal ends of all the thoracic ganglia, there is a large 
commissure (Fig. 17) which, in case of the prothoracic and 
mesothoracic, proceeds but a short distance and then forks and 
forms the diamond-shaped area in which the ventral sympa- 
thetic nerves are located. In both cases, the diamond-shaped 
area between the metathoracic and mesothoracic and between 
the mesothoracic and prothoracic ganglia occupies about 
two-thirds of the distance between the ganglia. 
Lateral Nerves——The lateral nerves (/) proceed from the 
gangha at their latero-cephalic part and are adjacent to the 
lateral edges of the commissures. The lateral nerves extend 
in a latero-cephalic direction. 
Connective Nerves—The connective nerves (c. n.) arise 
from the lateral edges of the commissure and extend in a caudal 
direction. In the case of the diamond-shaped area between the 
mesothoracic and metathoracic ganglia, the connective nerves 
arise midway between the anterior and posterior angles of the 
diamond. While, with the diamond-shaped area between the 
prothoracic and mesothoracic ganglia, the commissure gives 
rise to its connective nerves very much nearer the mesothoracic 
ganglion than to the anterior end of the opening. The con- 
nective nerves proceed a short distance caudad, then turn 
laterad and somewhat cephalad, and soon fuse with the lateral 
nerves laterad of their connection with the commissure. Before 
fusing with the lateral nerves, the connective nerves give rise 
