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1912] Anatomy of Tomato-worm Larva 
spiracles of each side open into the main, longitudinal trachea 
which extends between the spiracles and is amply long to allow 
for expansion of the body segments. A unique fact, to note in 
regard to these connecting trachez, is that each gives rise to 
small lateral branches varying from two to six or morein number. 
In examining specimens for transverse tracheal connections 
between spiracles of the same segment, none were found on the 
dorsal aspect except from the thoracic spiracle and the eighth 
abdominal spiracle. If other dorsal cross trachee exist, they 
must be very minute and delicate, for they were carefully 
sought. In the case of the eighth abdominal segment, only one 
minute dorsal cross trachea was found (Fig. 11), while in the 
prothoracic region, two distinct, cross tracheze were observed, 
the cephalic one being the larger and giving rise to two pairs 
of trachez, which proceed cephalad and ventrad into the — 
anterior portion of the head. The caudal cross trachea of the 
two gives rise to four or five minute pairs of trachee, which 
diverge in various directions. It should be mentioned, that 
the tracheal system varied considerably in minor details in 
different specimens. Looking on the ventral aspect for cross 
trachee, it was found that a small cross trachea existed near 
each ganglion of the nervous system (Fig. 13) except the supra- 
oesophageal ganglion, which is located dorsad and cephalad of 
the pharynx. ‘The cross trachez adjacent to the metathoracic 
and mesothoracic ganglia seemed to originate from branches 
of the connecting trachez between the first and second spiracles 
of the body. In all cases, with one exception, the cross tracheze 
lie ventrad of the nerve cord and in the abdominal region 
caudad of the ganglia. The one exception is the cross trachea 
that lies adjacent to the suboesophageal ganglion. In this case 
the trachea is dorsad of the commissure (H. 2g.). Each cross 
trachea on the ventral aspect gives rise to a pair of trachez that 
supplies the adjacent ganglion. 
MUSCULAR SYSTEM. 
In the gross treatment of the muscular system (Fig. 12) of 
this larva only the more prominent bands of muscles will be 
mentioned. The muscular system of the larva is segmentally 
arranged. The muscle fibres are confined in their extent to a 
single segment and furthermore the muscular arrangement is 
similar in each segment on the whole. This is especially true 
a 
