138 Mr. J. O. Westwood’s Memoirs 
liarity requisite from the dilated front of the body, which fills up 
the cell, and prevents access of air to the hind part of the body. 
The flight of these wasps is very peculiar, and quite unlike that 
of the Odyneri or Vespe@. The long hind legs are extended back- 
wards and downwards, reminding one of the flight of Faenus. There 
is a species of Tenthredo very nearly allied to JT. scrophularia, 
which I saw on the wing in September following, and which ex- 
actly reminds one of the flight of the Polistes. 
P.S.—The preceding details offer abundant suggestions in sup- 
port of the opinion, that it is principally by means of sight that 
insects, especially of the social species, are directed in their flights, 
and thereby enabled to retrace their steps to the hive or other 
dwelling place, and which has been maintained by Mr. Newport in 
a preceding page of the present volume. The cautious proceed- 
ings of my colony of wasps clearly indicated a gradual increase of 
knowledge of immediately contiguous objects ; but can we suppose 
it possible that the same kind of knowledge is obtained by the bee 
in a direct flight of several miles from its hive, especially at a time 
whilst all its attention and energies are devoted to the great busi- 
ness of its life, that of hunting for and pillaging flowers ? 
I shall here mention, in support of the power assumed to be 
possessed by insects, of obtaining knowledge by means of sight, a 
circumstance which I observed many years ago in Fleet Street, and 
which, although it indicates an error of sense, seems more com- 
pletely to establish the one in question than perhaps any previously 
recorded fact. Ona bright sunny day I observed a white butter- 
fly beating itself with violence against the outside of the panes of 
glass in a window on the north side of the street, on which the sun 
was shining with great force ; at first I could not comprehend what 
could induce this action in the butterfly, but the mystery was solved 
when, on looking into the window, I observed the many gaily co- 
loured labels of a chemist’s jars and packets placed on the opposite 
side of the glass. This had doubtless been mistaken by the butter- 
fly for flowers, which it endeavoured to reach in order to rob them 
of their sweets; of which of course the insect could have obtained 
no intimation by its sense of smell. How is it possible, with such 
facts as these before us, to adopt the conclusion of a work recently 
published, that insects are destitute of the senses? How is it pos- 
sible to arrive at so unphilosophical a conclusion, that the highly 
organized eye of an insect does not possess the sense of sight ? 
