OF THE TRACHEA IN INSECTS. 45 



SO that I am therefore unable to say what relation they would bear to that part of the 

 egg-tube which is free from tracheae. 



Oviduct. 



In Bonibus terrestris and several other species, the tracheae of the oviduct frequently 

 anastomose, so as to form meshes. In each mesh is one branch, ending in a tuft. The 

 branchlets composing the tuft are waved, and branch rather often. 



In B. muscorum the large tracheae do not anastomose so often as in the other species 

 I have examined. 



In Vespa they do not anastomose, and the branchlets often ended in tufts, with, however, 

 only a few tubules. 



In Ophion the oviduct is thrown into folds, and the trachese run transversely along 

 them. They are not very unlike those on the ovary ; but the branchlets are waved, which 

 is probably necessary on account of the movements of the organ. 



In Tenthredo, Locusta, and Carahiis, likewise, the tracheae resemble those on the egg- 

 tubes. 



In Cynips the tracheae end in tufts, consisting, however, of but few tracheae. 



In Ichneumon and Forficida I found no tracheae on the oviduct. 



In Necrophorus vespillo and N. hmnator the tracheae are in tufts as on the egg-tubes, 

 . but the tubules are far less numerous and more branched. They are a good deal hidden 

 by the irregularities of the organ, and altogether look very unlike those on the egg-tubes. 



In Libellula I did not get a very good view of the trachea? ; but they seemed to resemble 

 those of the ovary. 



The same is the case in Panorjxt ; but I did not see the tracheae well in tliis insect. 



In Eristalis the tracheae are, as usual, in large tufts. In Musca and Tipula also the 

 oviduct is very short, but I saw on it several of the usual tufts. 



In Aphropliora, on the contrary, they are quite unlike those of the ovary, being much 

 smaller and more delicate. They are, however, long and withoiit very many branchlets. 



In Pentatoma the tracheae resemble those on the stomach. 



Egg-canal. (PL III. fig. 15.) 



In Bomhus the tracheae do not inosculate as on the oviduct. The distribution of the 

 smaller brachlets, however, is similar ; but the tufts are fewer, more elongated, and the 

 tubules also less numerous. In Vespa they are nearly the same. In Ichneumon it seemed 

 to be free from tracheae. 



In Gryllus, Locusta, Carabus, and Necrophorus, the egg-canal is very short. 



In Panorpa it seemed to have very few tracheae. In Eristalis and Ilusca the tracheae 

 were in the usual tufts. 



In Aphrop)hora and Pentatoma they are like those of the oviduct. 



Supplementary O lands attached to the Beproductke Organs. 

 I have already stated that in this paper my attention is confined to the distribution of 

 the respiratory organs. In the names applied to other parts, therefore, I have followed 



