260 MODERN CLASSIFICATION OF INSECTS. 
form a tube, which is the pharynx, the extremity of this membrane 
being deflexed (fig. 89. 12, 13. x): if this, however, be removed 
(fig. 89. 14.), we perceive a beautifully delicate, erect, membranous 
valve which entirely closes the entrance into the cesophagus. The 
ease with which this complex machinery, which when at rest presents 
not fewer than four different foldings, is employed, is surprising. It 
is also to be observed that when folded up it is almost difficult to 
conceive where it can be placed so as to permit so little of it to be 
seen. This, however, is to be explained by the under side of the 
head being hollowed out for its reception. 
Another character of considerable importance in the classification 
of the bees is one which, from its immediate connexion with their 
economy, will not be considered less deserving of a detailed account. 
M. le Comte de St. Fargeau, following up the views of Latreille, has 
given an interesting notice of the organs employed by various bees 
for the collection of pollen, in the tenth volume of the Encyclopédie 
Meéthodique. ‘The larve of all the Mellifera feed either upon paste 
formed of honey and pollen, or upon honey alone; but as the females 
of nearly one third of the modern genera of bees do not possess organs 
enabling them to provide this paste (fig. 90. 19. hind leg of Sphecodes ; 
21. ditto of Hylzeus, destitute of polliniferous organs), they are com- 
pelled to deposit their eggs in the nests of other bees. These organs 
are of two kinds: the first consist of naked portions of the body, either 
slightly excavated or flat, with the margins fringed with hairs; this 
instrument has been termed “a palette,” which may be englished the 
pollen plate. It exists on the outside of the hind tibiz and basal 
joint of the tarsi of the neuter hive and humble bees (fig. 92. 19.), 
which are rather hollowed out, and in which species it is employed to 
carry pollen grains which have been saturated with honey. In other 
bees belonging to both the families into which the Mellifera are di- 
visible, such as Dasypoda, Andrena, Colletes, Halictus, and Panurgus, 
it exists upon each side of the metathorax, and the corresponding 
surface of the two posterior thighs (fig. 90. 7.), and is employed for 
the purpose of carrying plain grains of pollen, its sides being guarded 
by incurved hairs. The other instruments consist of bundles of hairs, 
whence they have been termed the scopa or scopula by Mr. Kirby, 
‘la brosse” by the French, and which we may call the pollen brushes 
(fig. 90. 7. and 91. 8.). All bees, indeed, possess brushes of hairs, 
the queen of the hive bee being the only known exception ; but these 
