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but soon again flew back to the window, where it had precisely the same difficulty in 
pulling its pulvilli from the glass as before; but after observing it some time, and at last 
trying to catch it, that I might examine its feet with a lens, it seemed by a vigorous effort 
to regain its power, and ran quite actively on the glass, and then flying away I lost sight 
of it." This observation it is not easy to explain, at first sight. Kirby thought "one 
might conjecture that from some cause (perhaps of disease) the hairs of the pulvilli had 
poured out a greater quantity of this viscid material than usual, and more than the 
muscular strength of the fly was able to cope with*. 
Revolving the subject in my mind, I have come to the belief that the fly in question was 
struggling against its impending death from " Empusa " ; some facts I have observed tend 
to confirm the idea, but time has not allowed of my working it out. 
The great knowledge of the habits of insects possessed by the author whose labours we 
are now considering, and of the remarkable adaptive modifications of different structures to 
their varying economy, enabled him to feel the necessity of always studying these in then 
mutual relations. " 
He also recognized the importance, for the purposes of a Natural Classification, of a 
thorough knowledge of the feet in insects ; and especially in the Coleoptera. His obser- 
vations on this head have been so thoroughly incorporated by Mr. Westwoodf (1839-AO), 
who has largely added to them, that the student will best consult the former through the 
last-named author. It does not consist with my present purpose to quote these observa- 
tions, which are rather for the entomologist ; but the value of the remarks on the feet in 
the different orders and genera, where they appear each under its proper head, is very 
great, and a valuable clue is thus furnished to one desirous of a guide to these parts in this 
numerically immense section of Animal Life. Mr. "Westwood's work is not a micro- 
scopical one ; yet the entomological descriptions of the feet given in it are so apt and 
expressive, that I shall avail myself frequently of them in the course of the following 
pages. 
The possession of a special apparatus by insects having climbing habits is mentioned 
as having been already skilfully pointed out ; and a remark also occurs of interest from 
the Coleopt 
nition of the similarity between the feet of the Hiptera and of some of 
" They [the Brachinides] are also characterized in many instances by having the tarsi 
dilated, and the penultimate joint more or less bilobed in both sexes, a peculiarity 
resulting, as Bonelli has observed from the situations in whicli they reside, this 
structure being in fact analogous to the cushioned feet of flies as well as of those of the 
true herbivorous beetles." 
I shall show how completely microscopic examination confirms the justice of this 
analogy, by the minute details of the respective structures. 
In Dr. Burnett's Translation of Siebold and Stannius's • Comparative Anatomy ' (185*). 
there appears in a foot-note a brief sketch of what the authors of this work considered the 
then state of knowledge on this subject. 
"Many of the Curculionidaj can grapple objects by means of the immoveable hooks on 
Introduction, 7th edit., p. 45 1 . 
f Introduction to the Modern 
