330 INSECTA. 



ologists with respect to the seat of the sense of hearing arid 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, oasophagus, 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 pharynx 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, professor 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. 



f This latter naturalist, whom I 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 Naturelles. Well arranged resum of the whole by M. Victor Audouin may 

 be found in the Diet. Class. d'Hist. Nat., article INSECTKS. 



