394 Remarks on the Antenna of Insects. 



rect, as though they were listening to discover the cause of 

 the annoyance : — there was as much uniformity of posture as 

 in a company of soldiers at their exercise. In a few seconds 

 they resumed their avocations, and "caressed" each other 

 as they passed on their upward or downward progress. I re- 

 peated the blow ; — they assumed the same posture as before ; 

 and this incident, simple as it may seem, led me to believe 

 that they were possessed of the power of distinguishing sound. 



A short time since I placed a Necrophorus Humator under 

 a wine-glass, about noontide; it soon became quiet in its pri- 

 son, and the plates forming the club of the antenna closed. 

 A few minutes afterwards, raising the glass and suspending it 

 about half an inch above the insect, I struck the edge with 

 my penknife ; the antennae were then moved about with ra- 

 pidity, the club dilated, and the insect sought to make its es- 

 cape; thus evincing that it was conscious of the sound pro- 

 duced, and also partly indicating that its antenna were the 

 organs by which the sound was conveyed to the brain. 



So far anecdotal inference, but we will proceed to test our 

 deductions by an appeal to fact. Mr. Newman says these 

 "cranial feelers" are "solid." The instant I read the passage 

 proof was at hand. Taking one of these "tactors" from the 

 head of a Trichiosma Lucorum, I cut it into two parts with a 

 pair of fine scissors; placing the lower portion under a mani- 

 fier, I found it hollow, — I could see down it as a tube. — 

 Increasing the magnifying power by adding another glass, and 

 afterwards a third, the fact became more apparent. I then 

 proceeded to examine in succession, several insects, among 

 which I may mention Phryganea grandis, Silpha opaca, Ge- 

 otrupes stercorarius, Dyticus marginalise Gomphocerus bi- 

 gustatus, Creophilus maxillosus, Bombus terrestris, Pontia 

 rapa, &c, and in every instance the antenna were hollow in 

 the centre. Being so far satisfied with my test, I imagined 

 it better to proceed to dissection. Taking a head of Cara- 

 bus nemoralis, I remeved the lower part ; then extracted the 

 first ganglion as far anteriorly as possible, without destroying 

 the muscles connected with the antenna. On taking away 

 the upper jaws, the power of the organ was perceptible, and 

 beautifully distinct. There was a hollow distended fibre, the 

 tympanum, at the base of the antenna, connected with nerves 

 that unite in the principal ganglion, or nervous centre, — the 

 brain, or focus of sensation ; — the auditory nerve expanding 

 from the tymprnum, penetrating and lining every annulation 

 of the antenna, from the base to the apex. Was this an op- 



