MR. NEWPORT ON THE RESPIRATION OF INSECTS. 
565 
Muscles. 
Fig. 1.1. The great dorsal and ventral recti. 
2. The smaller rectus. 
3. The middle line of insertion for the attachment of the greater recti and 
three oblique. 
4. The posterior or third line of insertion for the smaller recti and third 
oblique. 
5. The retractor of the stomach. 
6. The first oblique. 
7. 8. The second oblique. 
9, 10. The third oblique. 
1 1 . The fourth oblique. 
12. The third rectus. 
13. The fifth oblique. 
14. 16. The triangularis muscle. 
15. The transverse median muscles. 
17. The transverse abdominal muscles. 
18. The anterior abdominal. 
19. 20. The lateral abdominal. 
21. The sixth or posterior oblique. 
22. The seventh or postero-lateral oblique. 
23. The first transverse lateral muscle. 
24. The second transverse lateral muscle. 
25. 26. The retractor of the spiracle. 
27. The retractor of the valve of the spiracle. 
e. The longitudinal trachea of the right side, with its ramifications. 
f. A portion of the trachea cut away to show the entrance of the spiracle. 
g. The spiracle with the nerves and muscles belonging to it. 
Nerves. 
, 1 , k. The nervous column of the segments, exhibiting the ganglia of the sensi- 
tive tract traversed longitudinally by the motor tracts of the cords which 
terminate upon the last or double caudal ganglion, by dividing each into 
two portions, one of which is given to each of the four terminal nerves. 
It exhibits also the transverse nerves, forming a triangular plexus above 
the cords anterior to each ganglion, and passing laterally on each side to 
distribute their branches on the visceral surface of the muscles. 
a. The ganglion and transverse nerves. 
b. The transverse plexus. 
