538 
ARTICULATA. 
HEAD AND EYES OF THE BEE AS MAGNI- 
FIED BY THE MICROSCOPE. 
posed is thirteen ; but some of them are occasionally amalgamated together, or concealed by the 
others, so as to make it appear that fewer segments are present. 
The first segment, or the head, is composed of a single piece, which bears the eyes, the an- 
tennae, and the organs of the mouth. The eyes, w^hich are 
among the most wonderful objects in nature, are almost always 
of the kind called compound, that is to say, they consist of a 
multitude of little hexagonal facets, brought close together on 
each side of the head, each furnished Avith a cornea, a lens, a 
coating of pigment, and a nervous filament, and being in fact a 
true eye. The number of these minute organs is sometimes 
most extraordinary. The eye of the common house-fly has 
four thousand of them ; that of a dragon-fly more than twelve 
thousand; that of a butterfly observed by Puget, seventeen 
thousand three hundred and twenty-five ; and that of a small 
species of beetle — Mordella — no less than twenty-five thou- 
sand. In addition to these compound eyes, many insects also 
possess two or three ocelli, or simple eyes, placed on the head 
between the large compound organs ; these appear to be 
very similar in their structure to the individual eyes of which the compound eyes are com- 
posed. 
The antenn£e are usually attached to the front of the head, between the eyes. They are ex- 
ceedingly variable in their form, and probably vary considerably in function, although their gen- 
^^'i 0 of]/]/} ^^^^ office appears to be that of 
'rliiV ^mW/^ organs of touch. In some in- 
^!cV IvWl.lilL/ stances, however, their confor- 
mation appears to indicate that 
they are the organs of some 
special sense, and the functions 
of smell and hearing have been 
attributed to them by diff"erent 
observers. In their most or- 
dinary and simple form, they 
more or less filiform organs, composed of a very variable number of joints. Sometimes they 
thickened at the base, sometimes at the apex. In some cases the whole or part of the joints 
are furnished with one or more processes, bristles, or hairs, giving the entire organ a comb-like 
or feathered appearance. 
The structure of the mouth in insects exhibits very remarkable modifications, and these are 
of the utmost importance in the classification of these creatures. In some insects the mouth 
is formed exclusively for biting ; in others, as exclusively for suction ; while in others again it 
is fitted for the performance of both these actions ; and 
the form of its constituent parts of course undergoes 
corresponding changes; but the same organs really 
exist in all, modified in appearance, indeed, so as some- 
times to be scarcely recognizable. In the bees the 
organs of the mouth are adapted at once for biting and 
for suctional purposes, the elongated tongue constitu- 
ting a tube through which their fluid nourishment can 
be drawn in. In the butterflies the suctorial organ 
consists of a long trunk ; in the bugs it is a jointed 
rostrum ; in the diptera, or two-winged flies, a fleshy process, &c. The wings, legs, and feet are 
variously adapted to diSerent species. 
The abdomen consists generally of nine segments ; in some instances these are attached edge 
to edge, when the abdomen exhibits little or no flexibility ; in other cases, each segment slides 
ANTENNA OF YAKIOUS INSECTS. 
are 
are 
MOUTH AND TONGUE OF THE BEE, MAGNIFIED. 
