OF THE 
VCUEJE IN INSECTS. 
19 
imago, in those larvae which undergo a perfect metamorphosis (as, for instance, in those of 
Coleopt 
Lepidopt 
and Hyinenoptera) the trachea 
y 
unlike those of the 
perfect insect 
Sixthly, in these latter larva 1 the same type of tracheal distribution appears to he more 
widely distributed in the different organs. Thus, while in the ima^o of liomhus the 
tracheal on the stomach, ilium, and Malpighian vessels are all three very different from one 
similar t 
lie tracheae on the corresponding organs of the larva of B. muscoru 
) one another, and as in PI. II. fig. 11. Again, in the larva of L 
oesophagus, stomach, ilium, and colon, and in that of Lamp y vis the stomach, ili 
and Malpighian vessels, had tracheae respectively like one anoiher. 
Seventhlv, that in some cases the trachea- of the larva- seem to agree in spe 
/// are verv 
nam us the 
those of the perfect insect 
different ; so that, compai 
the precedin 
rule, it would seem that the larval tracheae are in both respects less dilleivntiated, and 
more in accordance with the original type than those of perfect insects. 
DESCRIPTION OF Tl 1 E PLATES. 
Plate I. 
F 
F 
F 
F 
F 
F 
F 
F 
F 
Tracheae from ganglion of Achcta, x 125. 
Tracheae from commissure of Carabus, x 125. 
Tracheae from ganglion of Bombus, x 125. 
Tracheae from commissure of Acheta, x 125. 
Tracheae from ganglion of Pejttatoma, x 125. 
Tracheae from ganglion of Carabus, x 125. 
Tracheae from commissure of Lasiocampa, x 125. 
Tracheae from oesophagus of Eristalis, x 125. 
o\ 9. Tracheae from sucking-stomach of Musca, x 125. 
g- 
1. 
g- 
o. 
g- 
\. 
g- 
4. 
g- 
5. 
6. 
g- 
7. 
g- 
8. 
Fig. 10. Trachea? from caecum of Acheta, x 30. 
Fig. 1 1 . Tracheae from caecum of Chrysopa. x 1 25 
Fig, 12. Tracheae from caecum of Chrysopa, x 125 
Fig. 13. Tracheae from crop of Carabus, x 30. 
Fig. 14. Tracheae from oesophagus of Musca, x 125 
Fig. 15. Tracheae from heart of Bombus, x 125. 
Fig. 16. Tracheae from heart of Musca, x 125. 
Fig. 17* Tracheae from heart of Aphrophora, 
x 125. 
Plate II. 
Fig 
from the stomach of Musca 
Fig. 2. A few of the larger tracheae- from the stomach of Pi ntatoma, omitting the finer branches, x 30 
Fig 
3. Tracheae from the stomach of Ophion, x 125. 
Fig. 4. Tracheae from the stomach of Acheta, x 60. 
Fig. 5. Trachea? from the stomach of Bombm, x 125. 
6. Trachea? from the stomach of Bombus, x 125. 
Fig. 7. One of the lateral branches from the above figure ofPentatoma 
Fig 
Ma 
x30. 
Fig. 8. Tracheae from the stomach of 
Fig. 9. Tracheae from the stomach of Acheta, x 30. 
Fig. 10. Tracheae from the stomach of Vespa, x 125. 
Fig. 11. Trachea? from the ilium of the larva of Bombus, x 125. 
Fig. 12. Tracheae from the ilium of Tipula, x 125. 
Fig. 13. Small part of the inner membrane of a trachea, showing the spirally thickened rib, a a a, x 125 
Fig. 
Fig. 
ary 
Anthoph 
Fig. 16. Trachea? of recurrent intestine of Aphrophora, x 30. 
VOL. XXIXL 
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