Limitation of the visual field of the worker honey-bee’s ocelli. by the rev. J. L. Zabriskie.9—The honey-bee is a remarkably hairy insect. On the head the hairs are dense, and of various lengths; and they cover every part, even the compound eyes and the mandibles. The antennÆ, however, are apparently smooth, having only microscopic hairs; and a path through the long hairs, from each ocellus, or simple eye, directly outward,—to be described more fully presently,—is practically smooth.

The ocelli are so situated that when the bee is at rest and the face vertical, they are directly on the top of the head, arranged as an equilateral triangle, and one ocellus is directed to the front, one to the right side, and one to the left10.

Long, branching hairs on the crown of the head stand thick like a miniature forest, so that an ocellus is scarcely discernible except from a particular point of view; and then the observer remarks an opening through the hairs—a cleared pathway, as it were, in such a forest—and notes that the ocellus, looking like a glittering globe half immersed in the substance of the head, lies at the inner end of the path. The opening connected with the front ocellus expands forward from it like a funnel, with an angle of about fifteen degrees. The side ocelli have paths more narrow, but opening more vertically; so that the two together command a field which, though hedged in anteriorly and posteriorly, embraces, in a plane transverse, of course, to the axis of the insect’s body, an arc of nearly one hundred and eighty degrees.

These paths through the hairs appear to me to be indications that the ocelli are intended for distant vision, although the opinion that near vision is their function is held by eminent opticians.

The ocelli are nearly hemispherical, and the diameter of each is about fifteen times that of a facet of the compound eye. Such a form of lens would, I will concede, indicate for these organs a short focus, and hence, a fitness for near vision.

But if the ocelli are intended for near objects, it is difficult to understand why they are surrounded by a growth of hair so dense as to permit unobstructed vision only in a very narrow field, and why they are so placed on the top of the head as to be debarred from seeing any objects in the neighborhood of the mandibles and the proboscis, the ability to see which objects would appear to be very necessary in the constant and delicate labors of the worker honey-bee among the flowers.

Dr. Zabriskie exhibited the head of the worker honey-bee for the purpose of illustrating the above remarks. At the conclusion of his observations, he added: “Besides the worker honey-bee, I have brought for exhibition the drone and the queen of the same species, and the queen-cells; the queen of Bombus Virginicus, one of our native humble-bees; the Melissodes binotata, male and female; the Melissodes pruinosa, both sexes; the beautiful Anthophora dispar, male and female of Tunis, Africa; and the celebrated little stingless bee of Abyssinia, the Trigona Beccarii, which lives in immense colonies, and stores large quantities of honey. The Anthophora dispar has a very long proboscis. The possession of such a proboscis by our own bees would add millions of dollars annually to the wealth of the United States.”