GENERAL HISTORY OF BEES. 
27 
which, lies between the upper extremities of the com¬ 
pound eyes. Upon the vertex are placed the stemmata, 
or ocelli (the simple eyes), in a curve or triangle; they 
are three in number, and are small, hyaline, circular 
protuberances, each containing within it a lens; some¬ 
times they occur very far forward upon the face, espe¬ 
cially when the compound lateral eyes meet above, as in 
the male domestic bee or drone. The uses of these 
simple eyes, from the experiments which have been 
made, seem to be for long and distant vision. To test 
their function, Reaumur covered them with a very ad¬ 
hesive varnish, which the bee could not remove, and he 
then let it escape. He found upon several repeated 
trials, that the insect always flew perpendicularly up¬ 
wards, and was lost. Although this was anything but 
conclusive as to the uses of these eyes, it would seem 
that by losing the vision of this organ, the insect lost 
with it all sense of distance. 
The compound eyes, seated on each side of the head, 
extend from the vertex generally to the articulation of 
the mandibles or jaws, their longitudinal axis being per¬ 
pendicular to the station of the insect. They vary in 
external shape and convexity in the several species and 
genera, although not greatly, and consist of a congeries 
of minute, hexagonal, crystalline facets, each slightly 
convex externally, and their interstices are sometimes 
clothed with a short and delicate pubescence. Each 
separate hexagon has its own apparatus of lens and fila¬ 
ment of optic nerve, each having its own distinct vision, 
but all converge to convey one object to the sensorium. 
The function of the compound eyes is concluded to be 
the microscopic sight of near objects. 
The face, which sometimes has a longitudinal carina, 
