﻿122 CLEMENS' SYNOPSIS OF 



his position in the air will return to the light in a direct line. This may be repeated 

 any number of times and will be followed invariably by the same result. Let the 

 antennae of the specimen then be excised in successive portions. The excision of the 

 upper third does not diminish the power to arrest itself, and to return again in a di- 

 rect line ; but beyond this point, flight begins to be impaired without effecting in any 

 manner the desire to return, until at least we reach a point where it becomes evident, 

 that the voluntary direction of flight is no longer under the volition of the insect, or 

 that some co-ordinating influence is wanting, having special relation to the direction of 

 flight, or the uses of the muscles of the alary organs. Instead of being capable of 

 arresting itself and returning in a direct path, the insect now darts from the point of 

 arrest to the right or left, to the ceiling or the floor ; and this uncertainty of direction 

 and inability to arrest the force of the impulsion continues to increase, until we reach 

 the neighborhood of the bulb, when the voluntary employment of the wings almost 

 ceases. 



All these results are obtained, simply by the excision of the pectinations of the an- 

 tennae, leaving the antennal stalks uninjured. The desire to fly is not affected in the 

 first place, and it is only after the individual ascertains the uncertain nature of his 

 efforts, that he fixes himself in a state of rest. 



The structure of the organs, together with these experiments, entirely justify the 

 inference : That the antennae, instead of being organs of any special sense as they are 

 usually regarded, are in lepidoptera instruments of atmospheric palpation, having espe- 

 cial reference to the action and use of the wings during flight. 



This conclusion has been reached contrary to my own preconceived ideas of the 

 function of these instruments, and I believe the view here taken is entirely new. 

 Should the experiments be repeated by any observer, he should be careful to select 

 for experimental study those lepidopterous insects, that are unprovided with simple 

 eyes or ocelli, on the vertex at the base of the antennae. In those species with ocelli 

 on the vertex, flight is deranged scarcely at all, as compared with the effect of antennal 

 excision on individuals unprovided with these organs. 



TEGULA 



These organs are also known by the names paraptera, paraptere, patagia, clavicide 

 anterieure, wing-covers, shoulder-covers. They are thoracic appendages which cover 

 the base of the anterior wings, and are concealed from view by the scales which cover 

 them and the thorax. They communicate with the interior of the thorax, by an 

 opening or foramen, in the fibrous tissue connecting the base of the wings to the tho- 

 racic walls. They are hollow corneous bodies, tapering from their insertion, where 

 alone they are fixed to the thorax, and the interior is unoccupied by any tissue what- 

 ever. The inner walls are lined with fibrous tissue, in which spiral tracheae are 



