Objects for the Microscope. 91 



and Bees. (See Antennae.) The wing-nerve branches 

 over the Elytron, and those dots which exhibit the black 

 cross with polarized light, are vesicles or organs of sensa- 

 tion, to which a distinct branch of the nerve may be traced. 



Soak the Elytron in potash for a week or more, and when 

 perfectly transparent mount in balsarn. 



The under wings exhibit groups of these vesicles on the 

 under side of the sub-costal nerve, as many as 200 and 300 

 in each wing. Observe the wing of Strangalia, a Longi- 

 corne Beetle. (See l Journal of Linnsean Society/ vol. i. 

 p. 136, Nov. 1, 1856). See also Elytra of Diamond Beetle. 



WING OF CRICKET. 



(Acheta, domestica.) 



This is mounted to show the organ of sound, the drum 

 and file by which the male Cricket chirps. Each of the 

 upper wings, or Elytra, has a round transparent space called 

 the drum, or tympanum ; at the base of each Elytron is a 

 transverse horny ridge, furnished with numerous short 

 transverse ridges or teeth, and forming a kind of bow or 

 file. The insect rubs the Elytra across one another, and 

 the grating of the files, together with the action of the 

 drum as a sounding-board, causes the loud chirp. Some 

 naturalists think that the legs work against this file and 

 produce the sound, particularly in the Grasshopper, whose 

 thighs are armed with rough ridges and short spines, and 

 act as the bow against the files and drum of the Elytra. 



The male Cricket only chirps. The female, silently at 

 home, occupies herself in laying about 300 eggs and in 

 rearing her brood. The tongue of a cricket is a beautiful 

 object. 



SCALES OF INSECTS. 



The feathers of a Moth, a Butterfly, a Gnat, the scales 

 of a Beetle, of a Weevil, of the Podura, are all both favourite 

 and useful objects for the microscope. It is well known to 

 every one that the dust which remains on our fingers after 

 touching a butterfly's wing is a mass of beautiful feathers r 



