OF THE TRACHEAE IN INSECTS. 
45 
that I am therefore unable to say what relation they would bear to that part of th 
egg-tube which is free from tracheae 
Oviduct. 
In Bombus terrestris and several other species, the trachea 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 tracheae run transversely alon 
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. 
(r 
In TenthredOy Locusta, and Carahus, likewise, the tracheae resemble those on the egy- 
tubes. 
In Cynips the tracheae end in tufts, consisting, however, of but few trachea. 
In Ichneumon and Forficula I found no tracheae on the oviduct. 
In Necrophorus vespillo and N. humator 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 tracheae ; but they seemed to resemble 
those of the ovary. 
The same is the case in Panorpa ; but I did not see the tracheae well in this 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 Aphrophora, on the contrary, they are quite unlike those of the ovary, being much 
smaller and more delicate. They are, however, long and without very many branchlets. 
In Bentatoma the tracheae resemble those on the stomach. 
Egg-canal. (PI. III. fig. 15.) 
In Bombus 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 Giyllus, Eocusta, Carabus, and Nec?*ophorus, the egg-canal is very short. 
In Panorpa it seemed to have very few tracheae. In Eristalis and Musca the tracheae 
were in the usual tufts. 
In Aphrophora and Bentatoma they are like those of the oviduct. 
Supplementary Glands attached to the Reproductive 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 
