THE HEAD. 45 



The Antennii6 appear to be among the most import- 

 ant of all the organs of the adult insect, and of a great 

 variety of forms and uses. 



They are filaments or feelers attached to the upper 

 part of the head which not only aid and guide the insect 

 in its motions, but which also probably serve as the 

 organs of several of the special senses, as feeling, hearing, 

 and smell. 



They may be observed in relation to their member^ 

 insertion substance^ situation, proportion, general form 

 and structure, clothing, expansion, motions, and state of 

 repose, and uses or functions. 



Insects invariably have but two antennae, while some 

 of the lower articulates, as the Crustaceans, have four. 



With the aid of an ordinary magnifying glass — or 

 even indeed, in most insects, without any such assistance, 

 the student may observe the details mentioned above, 

 such as form, structure, clothing, or covering, &c., with 

 a great degree of interest ; and so this outline will be 

 cumbered only with a few general hints. 



As to structure, antennge consist in general of a num- 

 ber of tubular joints, each being capable of an independ- 

 ant motion, and thus the insect is able to bend them in 

 every direction that may be required. 



Antennae, as to form, may also be regarded as tactile, 

 or tliose intended to explore the way of the insect by 

 means of touch ; and non-tactile — the short, thick an- 

 tennae, the last joint of which terminates in a bristle, or 

 is furnished with a lateral one, and which do not guide the 

 insect by the sense of touch. 



