In order to understand how a bee sucks honey it will be necessary to go
into some rather careful details as to the construction of its tongue and
mouth organs. These I will make as short and simple as I can, but the
apparatus is a very complicated one, and it will be impossible to describe
it without a good deal of technical phraseology.
The tongue has always been considered such an important feature in a bee's
structure that it has been made the chief basis of their classification. On
this subject I will only say that there are three principal types of
tongues--a short bifid tongue (fig. 19, 3[1]), resembling those of the
fossors; a short pointed one, shaped somewhat like a spear head (fig. 19,
2, 2a); and a long parallel-sided, ribbon-like tongue (fig. 19, 1, 1a). The
bees are classified on what is considered to be an {73} ascending scale,
beginning with the bifid-tongued species, through those with the short
spear shaped tongues to the higher forms, which have this organ elongate
and parallel-sided.
[Illustration: FIG. 19.]
The tongue is the central organ of an elaborate combination of mouth parts,
which I will now try to explain. If we turn a bee's head over and look at
its underside we shall find a deep cavity, filled up with the base of this
combination which fits into it. If we extend the tongue (a humble bee is a
good subject on account of its large size, fig. 20) so as to draw its base
out of the cavity, we shall find that in the edge of each side of the
cavity there is articulated a short rod (20, A), more or less dilated at
its apex, called {74} the _stipes_; on the flattened ends of these rods
there swings a joint shaped something like the "merrythought" bone of a
chicken, called the _lora_ or reins (20, B), to the central angle of which
are suspended the pieces of the apparatus which terminate in the tongue.
This V-shaped joint can swing over on its feet, and can therefore lie
either between the _stipites_ or rods with its angle pointing towards the
tail of the bee, or in the opposite direction with its angle projecting
beyond them and pointing forwards. It will at once be seen that by this
turn of the V the tongue can be projected a distance equivalent to twice
the length of the V.
This V-shaped joint varies much in the length of its arms, which are much
longer in the long-tongued than in the short-tongued bees.
When we examine the parts that are suspended from this joint, we shall find
that the actual tongue is separated from it by two distinct pieces; the
first (i.e. that next to the _lora_) a short joint (the _submentum_, 20,
C), the second (the _mentum_, 20, D) a long semi-cylindrical joint which
holds as in a trough the softer parts at the base of the tongue. From the
apex of the _mentum_ {75} project three organs; the central one is the
actual tongue (or _ligula_, 20, E), and on each side are the organs which
are called the _labial palpi_ (20, F); these in the long-tongued bees more
or less fold over the base of the tongue and protect it. There are two
other large and important mouth parts called the _maxillae_ (20, G); these
articulate on to the flattened apices of the _cardines_, outside the
articulation of the feet of the _lora_, and extend on each side of the
_mentum_; they also have flattened blades sheathing, when closed, the whole
of the _mentum_ above, as well as the base of the tongue.
[Illustration: FIG. 20.]
So far we have been looking at the back of the head and mouth parts; if we
now look at the front we shall see the _maxillae_; if we open these we
shall see the tongue lying between the {76} labial palpi, and at the base
of the tongue we shall see two little sheaths called the _paraglossae_;
above these the softer parts lying in the trough of the _mentum_; from the
base of the _mentum_, connecting with the _maxillae_, there extends a
membrane which entirely invests the spaces between the bases of these
organs and extends up to the mouth. A membrane also extends between the
_stipites_ and _lora_, and closes the cavity at the back of the head. The
back of the tongue in the act of sucking can be formed into a tube through
which, partly, probably by capillary action, partly by the pumping action
caused by the dilating and contracting of certain parts of the mechanism,
the liquid food is drawn up into the aesophagus. This, I believe, has been
shown to be the principle on which all bees, short- or long-tongued, suck
up their honey. The subject could be treated at much greater length, and
many other structures connected with the mouth parts discussed, but more
minute details are unnecessary in an elementary work such as this, and I
have therefore limited myself to a description of the broad principles of
the process.
* * * * *
{77}