All the solitary kinds appear to feed themselves on vegetable juices,
honey, etc., but there is a well-marked division between those who
provision the cells of their offspring with insects, either fully developed
or in the larval stages, and those who provision them with the pollen of
flowers, honey, etc. The theory is that originally all fed their cells with
insects, but that by degrees the more progressive found that the food which
suited themselves would equally nourish their offspring, and accordingly
provided them with vegetable nourishment. We find no intermediate stages. A
certain class still goes on feeding on the old principle. The members of
this class are known as "_fossors_" or diggers, while those which feed on
the new principle are called "_Anthophila_" or flower-lovers. These are not
very happy names, as many of the _Anthophila_ dig out holes for their nests
just {7} in the same way as the _fossors_ do, and many of the _fossors_ are
found in flowers, apparently enjoying them just as much as a truly
anthophilous species would, although no doubt often with the ulterior
object of capturing some insect for their young! Still these names are
known as representing these two sections all over the world, and therefore
it is better to keep to them even if they are not as descriptive as one
would like them to be.
The _fossors_, or "diggers", have all comparatively short and bifid
tongues, and have, as a rule, little in the way of hairy covering, and what
hairs they have are simple and only in very rare instances branched or
feather-like. The hind legs of the females are not modified in any way so
as to enable them to collect pollen, their legs are usually long and
slender, and they are admirably adapted to their life habits of hunting
spiders, insects, etc., for their young.
On the other hand, the _Anthophila_ or "flower-lovers", are specially
adapted for pollen collecting. Their tongues vary from a short form like
that of some _fossors_ to the long tongues of the humble bees. Their hairs
are always plumose {8} or branched on some part of the body and the hind
legs of the females in most species are provided on the tibia or shin with
a special brush on which pollen may be collected. In some of the
long-tongued bees, however, this brush occurs on the underside of the body
instead of on the tibia. The pollen-collecting arrangements of the
different genera of the _Anthophila_ and the corresponding organs for
cleaning off the pollen again are amongst the most interesting instances of
modification and adaptation: some of the more striking of these will be
mentioned later on. (See pp. 65 _sqq._)
* * * * *
{9}