250 SENSES OF INSECTS. 



cated to its sensory. A similar disproportion is observ- 

 able between the antennae and ovipositor of Pimpla 

 Manifest ator, before signalized a . Bees, when collecting 

 honey and pollen, first insert the organs in question into 

 the flowers which they visit ; but, as I have more than 

 once observed, they merely insert the tip of them. If 

 anthers are bursting, or the nectar is exuding, these 

 processes probably are attended by a slight noise, or 

 motion of the air within the blossom, which, as in the 

 last case, affects, without immediate contact, the ex- 

 ploring organs. 



If the structure of antennae be taken into consideration, 

 it will furnish us with additional reasons in favour of the 

 above hypothesis, with regard to their primary function. 

 We shall find that these organs, in most of those insects 

 which take their food by suction, are usually less gifted 

 with powers of motion, than they are in the mandibulate 

 tribes ; so that in the majority of the Homopterous He- 

 miptera and Diptera, as is generally acknowledged, they 

 cannot be used for touch. Under this view, they may 

 be divided into active antennae and passive antennae : of 

 the former, the most active and versatile are those of the 

 Hymenoptera. By means of them, as was before ob- 

 served 5 , their gregarious tribes hold converse, and make 

 inquiry frequently without contact in the pursuit and 

 discharge, if I may so speak, of the various duties de- 

 volved upon them by PROVIDENCE. Amongst active 

 antennae, some are much more complex in their struc- 

 ture than others a circumstance which is often charac- 



* See above, p. 218. b VOL. II. p. 64, 198. 



