658 Laura Florence 



breaking up into innumerable tracheoles, pass through the lateral muscles 

 and support the digestive and reproductive organs from their ventral 

 aspect. Between segments 7 and 3, eight branches are given off centrad 

 from the lateral trunks. These pass to the dorsal muscle plate, the heart, 

 the dorsal fat cells, and the surface of the alimentary tract. 



In some species, roots of branches extending laterad from the main 

 trunks, between the branches to the stigmata of segment 3 and the thorax, 

 have been described by investigators who have regarded them as vestiges 

 of branches to the lost stigmata of segments 1 and 2. Such roots have 

 not been found in this case. In the region of the second segment two 

 slender branches are given off, one laterad and the other centrad. The 

 former soon bends downward and breaks into numerous tracheoles on 

 the surface of the salivary glands, while the latter ramifies among the fat 

 cells on the dorsal anterior region of the stomach. Under the sternite 

 of the first segment a slender branch comes off from each main trunk and 

 passes to the dorsal surface of the stomach, and a second fine branch 

 arises where the main tracheae bend somewhat ventrad as they pass 

 into the thorax. This branch breaks up in the thoracic muscle of the 

 third pair of legs. 



In the thorax the main tracheae bend underneath the muscles coming 

 from the legs to the metathoracic apodeme. In line with the third pair 

 of legs a very short branch is given off laterad, from the posterior side 

 of which arise two branches, one passing directly into the leg, and the 

 other centrad for a short distance, when it divides into three parts. The 

 first part of this branch is the commissure of the metathoracic ganglion, 

 the second ramifies on the ventral wall of the stomach, and the third 

 bends laterad passing into the leg. Opposite the second pair of legs is 

 a tracheal plexus, from which spread six large branches as well as many 

 small branches supplying the surrounding muscles and fat cells. A stout 

 dorsal branch connects the plexus with each thoracic stigma. The first 

 branch going cephalad divides, one part passing , laterad to the first pair 

 of legs, the other passing centrad as the commissure of the prothoracic 

 ganglion, first giving off a branch which turns backward aiu! also enters 

 the first pair of legs. The second branch going cephalatl is a continuation 

 of the lateral tracheal trunk and passes to the head. A branch passes 

 directly centrad as the commissure of the mesothoracic ganglion and 

 from it a branch arises at the lateral border of the ganglion and bends 



