INSECTS 1439 



with purposes of warfare. Wherever it occurs it is 

 always confined to the female sex, or (as in the case 

 of some social insects) to the neuters, which are 

 undeveloped females. When it is not accompanied 

 by a poison-reservoir it is ancillary to the deposition 

 of the eggs, and is hence called an ovipositor, though 

 in many cases it performs a part much more exten- 

 sive than the mere placing of the ova. 



A very wide field of observation, and one easily 

 cultivated, is presented by the organs of sense in the 

 insect races, and in particular by those curious 

 jointed threads which proceed from the front or 

 sides of the head, and which are technically called 

 antennae. These may sometimes be confounded with 

 the palpi; for in a carnivorous beetle, for instance, 

 both palpi and antennae are formed of a number of 

 oblong, polished hard joints, set end to end, like beads 

 on a necklace. And it is probable there may be as 

 much community in the function as in the form of 

 these two sets of appendages; that both are the 

 seatc of some very delicate perceptive faculty allied 

 to touch, but of which we can not, from igno- 

 rance, speak very definitely. It is likely, indeed, 

 that sensations of a very variable character are per- 

 ceived by them, according to their form, the degree 

 of their development, and the habits of the species. 

 It is not impossible, judging from the very great 

 diversity which we find in the form and structure of 

 these and similar organs in this immense class of 

 beings, compared with the uniformity that prevails 

 in the organs of sense bestowed on ourselves and other 

 vertebrate animals, that a far wider sphere of per- 



