432 Dr. Goring on Achromatic Microscopes* 



ing must be considered as having been taken from a dried 

 specimen instead of a recent one, (as it should have been,) 

 for it is an object which is sure to be much changed, warped, 

 and shrivelled up, if detached from a newly-killed fly, even 

 for one hour only. However, as the prominent features 

 which constitute the peculiar subjects of examination as tests 

 were well preserve^, the drawing will do well enough to 

 point out what I wish to submit to my readers' consideration. 



Fig. 12. 



At a is to be seen a fluting in the claw ; b, b, b, b, b, are 

 lines, furrows, or flutings in the hairs of a v/hitish tint ; c is a 

 species of scale-work on the shank somewhat similar to what 

 may be observed on the feet and legs of birds ; d d are mi- 

 nute white dots, probably the orifices of glands, dispersed 

 over the whole of the inferior surface of the suckers as re- 

 presented in the plate ; ^ is a fringe of hairs round the mar- 

 gin of the suckers, with minute globules at their termina- 

 tions. 



Now all these minutiae can be seen, in more or less perfec- 

 tion, in every good specimen. I must observe, however, of 

 the dots or granulations on the soles of the feet, that they 

 are sometimes not visible, owing to the whole surface being 

 occasionally furred over with dust, dirt, and other extraneous 

 matter, which is apparently licked up by the glutinous fluid 

 which exudes from the orifices of the glands. I think that 

 kind of light which is afforded by a silver cup does best upon 



