26 THE CLASS OF INSECTS. 



The Antennae (Figs. 35, 36) are inserted usually in the adult 

 insect between, or in front of the eyes, though in the embryo 

 they are inserted below and in front of the eyes. 

 It is normally a long, filiform, slender, many- 

 jointed appendage, undergoing great changes 

 in form. When it is highly specialized, as in 

 Coleoptera and Hymenoptera, it is divided 

 into three parts, the basal or scape, the middle 

 or pedicel, and the terminal part or flagellum, Fi s- 36 - 

 Fig. 35. or davola, which usually comprises the greater part of 

 the antenna. 



It is believed by some that the sense of hearing is lodged 

 in the antennae, though Siebold has discovered an auditory 

 apparatus situated at the base of the abdomen of^ some, and 

 in the fore-legs of other species of Grasshoppers. 



Mr. J. B. Hicks has made the latest studies on the auditory 

 apparatus. According to him "it consists first of a cell, sac, 

 or cavity filled with fluid, closed in from the ah* by a mem- 

 brane analogous to that which closes the foramen ovale in the 

 higher animals ; second, that this membrane is, for the most 

 part, thin and delicate, but often projects above the surface, in 

 either a hemispherical, conical, or canoe-shaped, or even hair- 

 like form, or variously marked ; thirdly, that the antennal nerve 

 gives off branches which come in contact with the inner wall of 

 the sacs ; but whether the nerve enters, or, as is most probable, 

 ends in the small internally projecting papilla which I have 

 shown to exist in many of these sacs, it is very difficult to say. 

 The principal part of the nerve proceeds to these organs, the 

 remaining portion passing to the muscles, and to the roots of 

 the hairs, at least to those of the larger sort." On the other 

 hand, Lefebvre, Leydig, and Gerstaecker regard this so-called 

 "auditory apparatus" as an organ of smell. 



The antennae have also the sense of touch, as may readily be 

 observed in Ants, Bees, and the Grasshopper and Cockroach. 

 "The Honey-bee, when constructing its cells, ascertains their 

 proper direction and size by means of the extremities of these 



FIG. 35. Filiform antenna of Amphizoa. From Horn. 



FIG. 36. A, lamellate antenna of a Lamellicorn Beetle; B, antenna of a Fly, 

 with the bristle thrown off from the terminal joint; C, bristle-like antenna of a 

 Dragon-fly, Libellula, From Sanborn. 



