298 BONSDORF ON THK ANTENN.E OF INSECTS. 



very great minuteness of these renders it difficult for us to perceive 

 them. 



There remains only one doubt, which the diligence of an after age 

 may remove, namely, what openings the tremulous waves of sound may 

 have reserved for them in the inmost recesses of the antennae, since 

 these organs are terminated by no open mouth ; or whether these pores 

 and openings between the joints be concealed, by which the very tender 

 members connecting the joints alternately may be struck, for which use 

 these holes invisible to the naked eye seem clearly to be arranged, and 

 fitted equally for hearing, as the smallest bones of the semicircular 

 canals in the larger animals. 



Nothing more therefore is requisite in this case for confirming this 

 opinion, than to show that the antennae are active and watchful 

 whenever they are exposed to hostile and sudden sounds. 



I have examined by many and various experiments for several years 

 insects of different kinds, in which the size of the antennae was different, 

 and such experiments, provided due care and attention are employed, 

 cannot be performed without the most striking results. In proportion* 

 also, as the summer season was agreeable and the weather mild and 

 serene, my success was greater and more delightful. As all my observa- 

 tions agreed in this one circumstance, I omit to enumerate them ; for the 

 antennas being erect as soon as they were put on the alert, they were 

 moved hither and thither by means of loud sounds, for they disregarded 

 such as were very small. These they may be said to have drunk in ; 

 and if alarmed by new sounds they rejoiced when they could effect 

 their escape as soon as possible, and preserve life and safety by the most 

 rapid flight. So I have observed very frequently when the antennae 

 were folded up in the Lcptura, Elateres, Curculiones, Papiliones, 

 Apes; nay, even the housefly, as soon as they were moved and ex- 

 cited by irregular sounds or noise, would erect their antennae and 

 betake themselves to flight without any other excitement. The 

 Sphinxes again, and Pkalcente, during the night, fly about the flowers 

 of the marragon and other lily plants, emitting an agreeable smell ; 

 during the night, scarcely could a voice be raised than they would turn 

 round very swiftly, and the antennae appear to be, as it were, convulsed. 

 I must not pass over in silence, however, that no evidence more clear 

 could be desired of t the sensibility of the antennae to quick sounds, than 

 what occurred to me last summer in my garden. I observed in a morn- 

 ing walk, undertaken for the purpose of catching insects on the hazels, 

 that while standing in the shade a nut weevil Avas sitting quietly at a 



