282 ANNUAL OF SCIENTIFIC DISCOVERT. 



special sense, and tonic rigidity of the muscles, they may at this stags 

 be instantly restored to the opposite condition of extreme mobility and 

 exalted sensibility, by directing a current of air against the organ or 

 organs we wish to render limber, and which had been in the catalepti- 

 forni state. By mere repose, the senses will speedily merge into the origi- 

 nal condition again." Now, none of these processes, in inducing sleep, 

 would be applicable to insects whose eyes are immovable, if the provis- 

 ion for seeing was confined to the two large globular eyes on each side 

 of the head f" but being provided with ocelli, or auxiliary eyes, placed 

 on the vertex of the head, these facts illustrate the drowsy insect. The 

 structure of these auxiliary organs is just that of one of the lenses of 

 the compound eye ; but being so placed that they can be set close ^ to 

 what they examine, and can concentrate the attention to the exclusion 

 of the objects that occupy the globular facetted eyes, it is possible that 

 such visual concentration, when the insect retires to repose, induces 

 just that perceptive vibration described in cataleptic sleep by which 

 slumber can be brought on. 



An insect composes itself to sleep with its antennsa folded. Some 

 of the beetles adjust them to their breast ; the butterfly seeks some 

 particular aspect of a tree, aud folds vertically its wings, throws back 

 the antennae, and remains motionless and insensible to all external cir- 

 cumstances. When caterpillars, which are insatiable feeders, are ob- 

 served resting immovable with their heads bent down, they are asleep. 

 The geometers may be remarked stretched out for hours projected 

 from a twig resembling the angular stem of those trees they are feeding 

 upon, and the processionary caterpillars, whose night marches, in mar- 

 shalled communities, are regulated with such remarkable exactness 

 that they resemble battalions^platooning over a field, in " strict love of 

 fellowship combined " in passing the day in inaction, spend it in re- 

 pose. 



Whatever may be the controlling cause that renders some insects 

 diurnal feeders and flyers, and some nocturnal and crepuscular movers, 

 frolicking or feasting in the twilight, the solution must be sought in the 

 adaptive differences that regulate the " sleep of plants" Some plants 

 repose by night ; others expand in the darkened hours, and slumber 

 under the stimulation of light. Whether the closing of the flower be 

 at nightfall, or its opening be as soon as daylight fades, or whether it 

 be the reversal of this order, the differences are precisely the same as 

 in those animals that sleep through the day and awake at night, or 

 that awaken in light and slumber in darkness. The regular intervals 

 that lead to sleeping or waking are the recurrences of those electrical 

 incidents that attend the interchanges of day and night in the atmos- 

 phere. 



THE EYES OF BEES. 



Men never knew what the eyes of bees really were, until the greatly- 

 improved microscopes of the present day, in effect, gave us another eye 

 to gaze upon those of bees. They have simple eyes, three in number, 

 and disposed in a triangle between the two compound eyes. The lat- 

 ter are wonderful objects under a microscope. The compound eye of 

 a bee, particularly of a drone, is one of the most exquisitely constructed 

 instruments of nature's handiwork. One of the leaves of chaff' that 



