140 



characters of the different orders of true insects (especially with reference to their larva 

 state and extent of subsequent development), adopting two primary groups, Mandibu- 

 lata and Haustellata, placing the Neuroptera as the lowest of true insects, preceded by 

 Coleoptera, Orthoptera, Hymenoptera, Hemiptera and Diptera,the Lepidoptera, " in the 

 character of their wings, as well as in all other respects, ranking highest among Haustel- 

 lata, and therefore amoug all insects." " The same evidence also which shows Lepido- 

 ptera to rank highest among insects, shows also that insects as a class rank higher than 

 Crustacea." The larva of the Lepidoptera represents perfect worms; the chrysalis, in 

 the junction of the head and thorax into an enlarged shield, with the abdomen free 

 and movable, represents perfect Crustacea, and the true insect is above all. So also he 

 further regards the Mjriapoda as worm-like insects or larva -like insects, the spiders as 

 Crustacea-like insects or pupa-like insects, " and the true insects as the highest stage of 

 development, ranking above all.'' These views are developed with much ingenuity and 

 at considerable length in the 1st and 5th sections of the Memoir, accompanied at the 

 same time, as it appears to me, with just such an amount of direct general observation, 

 mixed with assertion and assumption, as to give an appearance of vraisemblance to the 

 argument,* which a more precise view of the subject does not appear to warrant.f 

 In his second section, the author has detailed the transformations of one of the North 

 American Hesperidae — Eudamus Tityrus, especially describing the changes which 

 take place on assuming the pupa state, and on passing from the pupa to the imago, 

 and dwelling especially on the fact, which he believed to be a new discovery, that the 

 limbs of the pupa are at the first free and detached from each other ; a fact, however, 

 well known ever since the days of Swamiuerdam, whose figures in illustration thereof 

 are even more intelligible than those of Agassiz. With regard to the manner in which 

 the limbs of the pupa become firmly and closely affixed on the breast in a mass, the 

 author appears to be unaware that it is due to the existence of a gummy liquid, se- 

 creted by the insect at that period, attributing it to the pressure caused by the pupa 

 escaping through the narrow slit on the back of the skin of the larva. The skin, legs, 

 wings, antennae and jaws are erroneously said to be thus fixed together. In like manner 

 he describes the well-known pupa of Musca vomitoria (inclosed within the indurated 

 skin of the larva) as a fact of which previous entomologists had been ignorant, or had 

 not properly considered with reference to its analogy with the pupa of Culex ! The 

 only new fact which I find in this Memoir, is the manner in which the Hesperidae at- 

 tach themselves by silken threads in the pupa state, namely, by fixing themselves with 



* For instance, the assertion that " however extensive the metamorphoses of the 

 Coleoptera, Neuroptera, Hymenoptera and Diptera may be, they do not rise in any of 

 these orders beyond the development which the Lepidoptera attain in their pupa con- 

 dition, as in the pupa of Lepidoptera the jaws are already transformed into a sucker- 

 like proboscis when wings and legs are developed," is at once disproved by the fact 

 that the jaws of the larvae of Lepidoptera become obsolete in the perfect insect, and 

 that it is the maxilla; of the larva which are developed into the tubular sucker of the 

 butterfly. So, again, in asserting that the type of the jaws of the Diptera is interme- 

 diate between those of Hemiptera and the perfect Lepidoptera, we have a confusion 

 of ideas arising from three separate organs being brought into comparison ; namely, 

 the mandibles of the Diptera, the maxillae of the Lepidoptera, and the labium of the 

 Hemiptca. 



-}■ In this respect the memoir bears a curious resemblance to the ' Vestiges of Creation.' 



