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, 



