Volume 4 — FOOTNOTES:

But there are circumstances that militate against this hypothesis. The analysis which Lyonet has given of the fluid contained in the dorsal vessel of the Cossus[391], seems to prove that it is more analogous to gum or varnish. He saw indeed a few globules, which appeared ten times as big as the others, which swam upon the water, but which he did not regard as component parts of the fluid, but as little drops of grease extravasated by dissection. The fluid of the vessel itself easily mixed with water, and appeared to sink in it to the bottom[392]. This proves that it is not of a fatty or oleaginous nature. But the strongest objection is stated by M. Carus, who judiciously observes[393], That it is contradictory to suppose that a canal should absorb or exude fluids by its parietes in a different form. Further experiments however seem necessary to ascertain the nature of the fluid and its object.

An Acrida with this spot is figured by Professor Lichtenstein. Linn. Trans. iv. t. v. A.

Palpi four: anterior pair pediform, cheliform, or unguiculate; posterior pediform.

Trunk Legs six, &c.

The obvious primary sections of the Lepidoptera, which have been evident to almost every one who has at all studied the Order, are the three named in the text, corresponding with Linné's genera Papilio, Sphinx, and Phalæna. The groups of the last or nocturnal section, which Dr. Horsfield has elevated to the same rank with the two first, are evidently not of equal value, nor to be placed upon the same platform; for the Bombycidæ, Noctuidæ, and Phalænidæ, are clearly of a secondary rank. Indeed this section is resolvable into more groups of equal value than the learned Doctor has assigned to it; for the Tortricidæ, Tineidæ, &c. are not so united to the Geometers, or genuine Phalænidæ, as to form with them a primary group of the Nocturnal Lepidoptera, but are themselves entitled separately to that distinction. This will be evident to every one who will take the trouble to compare the larvæ and their habits, of the two tribes, as well as the perfect insects.

In the construction of his groups, he seems not to have discovered in the Lepidoptera a great typical group resolvable into two, or at least he has not built his system on this foundation, which appears an essential part of the quinary arrangement. (See Mr. W. S. MacLeay in Linn. Trans. xiv. 56—.) As to value, the Papilionidæ constitute the typical group or centre of the Order, though the Phalænidæ prevail as to numbers: but neither of these are resolvable into two primary groups.

With regard to works in British Entomology in general—Donovan's Natural History of British Insects, and Samouelle's Entomologist's Useful Compendium, will be found very excellent helps to the student. For the British Genera, the most important work that has yet appeared is Mr. John Curtis's British Entomology, in which not only are the insects admirably represented, but their trophi correctly delineated, accompanied by able descriptions. For the Coleoptera of our country, Mr. Marsham's Entomologia Britannica should be consulted: for the Lepidoptera, the Butterflies of Lewin, Mr. Haworth's useful Lepidoptera Britannica, and Miss Jermyn's Butterfly-Collector's Vade Mecum; and for the English species of Linné's genus Apis, the Monographia Apum Angliæ. A British Fauna Insectorum, under the title of Illustrations of British Entomology, has at length been happily begun by a gentleman (J. F. Stephens, Esq.) who both by his accurate knowledge of the subject, and the extent of his collection of British Insects, is best qualified to undertake it. As far as it has proceeded, it is ably executed, and possesses this advantage, (an advantage seldom to be obtained in works published periodically,) that it finishes, as far as possible, as it goes.