EXTERNAL ANATOM>* OF INSECTS. 523 



apex of the slate-coloured joints of its antennae is bearded 

 with black hairs. In Lamia reticulata, and Saperda 

 fasciculata and plumigera, all also Capricorns, a single 

 bunch of hairs, resembling the brush of a bottle-cleaner, 

 signalizes the middle of the antenna a : in Saperda sco- 

 pulicornis K. this is star-shaped b . Sometimes the scape 

 is externally bearded, as in Trar, a beetle found in horns 

 and bones ; and in many other Lamellicorns c . In this 

 last tribe the two exterior leaves of the knob of the an- 

 tennae are often set with short bristles d ; and in a minute 

 beetle called by De Geer Dermestcs atomarius, the hairs 

 of this part are said to form a brush e . 



When insects, I mean more particularly Coleoptera, 

 are about to move from any station where they have 

 been at rest, the first thing they usually do, before they 

 set a step, is to bring forward and expand their antennae, 

 which have either been carefully laid up in a cavity fitted 

 to receive them, or back upon the body: if they termi- 

 nate in a lamellated knob, they separate the lamellae as 

 far as possible from each other; or if it is perfoliate, the 

 joints of it mutually recede. The object of this is evi- 

 dently to collect notices from the atmosphere, since the 

 papillose part of these joints cannot be applied to sur- 

 faces. When the animal begins to move, in many cases 

 the antennae do the same, and continue their motion till 

 it stops and returns to a state of repose. In the parasitic 

 tribes of the Hymenoptera {Ichneumon L.) they are kept 

 in an almost constant vibration. Many other insects 

 move them in all directions without any order or regu- 



a Plate XII. Fig. 25. b Plate XXV. Fig. 17. 



c Linn. Trans, xii. /. xxiii.f. h.f. '' Ibid, tTxxi. f. 8 g. 9, 10. e. 



p De Gecr iv, 219. /. viii./. 20. 



