330 
INSECTA. 
ologists with respect to the seat of the sense of liearing and of smell. 
We will merely add, in regard to the former, that the little nervous 
frontal ganglions of which he have spoken, seem to confirm the 
opinion of those who, like Scarpa, place it in the origin of the an- 
tennae. I have detected two small orifices near the eyes of certain 
Lepidoptera, which, perhaps, are auditory canals. If, in several 
Insects, particularly those furnished with filiform, or long, setaceous 
antennae, they (the antennae) are organs of touch, it seems to us 
difficult to account for the extraordinary developement they acquire 
in certain families, and more particularly in the males, if we refuse 
to admit that they are then the seat of smell. The palpi also, in 
some cases, as when they are greatly dilated at the extremity, may 
possibly be the principal organs of smell, part of which sense may 
also perhaps belong to the ligula. 
The digestive system consists of a preparatory or buccal apparatus, 
intestinal canal, biliary vessels, also called hepatic vessels, those styled 
salivary, but which are less general, free and floating vessels called 
excrementitious, the epiploon or corps graisseux, and probably of 
the dorsal vessel. This system is singularly modified according to 
the difference of the aliment, or forms a great number of particular 
types, of which we shall speak when treating of families. We will 
merely say a word with respect to the buccal apparatus and the prin- 
cipal divisions of the intestinal canal, beginning with the latter. In 
those where it is the most complicated, as in the carnivorous Coleop- 
tera, we observe a pharynx, oesophagus, crop, gizzard, stomach or 
chylific ventricle, and intestines which are divided into the small in- 
testines, great intestine or caecum, and the rectum. In those Insects 
where the tongue, properly so called, is laid on the anterior or inter- 
nal face of the lip, or is not free, the phaiynx is situated on that same 
face and this is most commonly the case *. We will also add, that 
a naturalist who first furnished us with correct observations on the 
respiratory organs of the Mygales, M. Gaede, jirofessor of natural 
history at Liege, does not consider the biliary vessels as secreting 
organs — this opinion, however, does not appear to be sufficiently 
well founded, and the observations of M. Leon Dufour f . even seem 
to destroy it. 
* See what we have stated respecting the ligula, in our general remarks on the 
three classes. 
-h This latter naturalist, whom 1 shall have frequent occasion to mention, has 
published, with the most minute detail, every thing relative to the digestive system 
of Insects, in a series of admirable Memoirs, which have enriched the Annales des 
Sciences Naturellcs. Well arranged resumti of the whole by M. Victor Audouin may 
be found in the Diet. Class. d’Hist. Nat., article Insectes. 
