OF THE TRACHEAE IN INSECTS. 37 



In Gryllus also and Forficula the mode of brandling lias much similarity to that of a 

 tree ; but in neither did I trace the line tubules. In the larva of Acheta the termination 

 of the tracheae, so far as it could be seen, resembled that of the perfect insect. 



In Melolontlia, Scarahcetis, and Lucanus I met with the same difficulty. In the larva 

 oi Lampyris and in that of Lucanus the distribution was much the same (PL II. fig. 6). 

 In Necrophorus vespillo and N. humator the branchlets are long, waved, not very nu- 

 merous, and without any special peculiarity in the mode of brandling, which is generally 

 more or less dichotomous. The organ is provided with numerous white finger-like glands, 

 on which the waved tubules had a beautiful appearance. Gener illy one or two run up 

 each gland. 



The distribution of the trachea} in Libellula is very peculiar. Two large trachese run 

 along the stomach and give off about eight large transverse branches on each side in pairs. 

 These lateral branches again give off branchlets at right angles, and these again others 

 at acute angles. These last often run into one anotlier, and thus divide the organ into 

 numerous elongated compartments. 



In Panorpa about ten large trachea} go to the stomach, on which they ramify in a 

 radiating manner. There are also a few smaller systems, but by far the greatest number 

 of tracheae originate from these large branches. 



The tracheae of Chrysopa and of Mamestra brassicce (larva) resembled those of Tenthredo 

 and Cynips, but I did not notice such long unbranched tubes. Sometimes the tracheae 

 were here and there in tufts. Those of Campcea margaritaria were still more like those 

 of Tenthredo and Cynips, while Hipparchia again agreed with Chrysopa. 



In Musca and Eristalis the tracheae are in very pretty tufts. The ends of the tubules 

 often run into the spaces occupied by other systems, but they very seldom inosculate. 

 Sometimes the systems are more elongated, so as almost to lose the appearance of tufts. 

 When magnified about 100 times, the tracheae have a beautiful appearance. 



In the larva of Musca the stomach is well supplied, principally by transverse branches, 

 which, however, do not end in tufts. On the anterior part especially they are very 

 pretty. 



In Tipida the trachea; are but very loosely attached to the stomach, so that they may 

 easily be torn off in the dissection. They are not in tufts like those of Musca and Eristalis, 

 but resemble those on the ilium. 



In Aphrophora spumaria the trachete are not very numerous, and consist of long 

 waved branchlets, with few ramifications, much, in fact, like those of Lampyris and 

 Necrophorus. 



In Pentatoma the stomach is complicated. PI. II. fig. 2 represents one of the tracheal 

 branches magnified 60 times, and fig. 7 one of the lateral branchlets magnified 250 

 times, of the anterior part. The branchlets divide dichotomously, and also throw out 

 numerous tubules from the side. The tubules often run close together for some distance. 

 On the posterior sacculated part of the stomach are thick, broad tracheae Avhich send 

 out large branches. These run principally between the sacculi, and appear to branch like 

 those of the front part of the stomach. It is, however, difficult to follow them satis- 

 factorily, on account of the folds. Finally, there is a broader, short chamber, into Avhich 



