50 



CHAPTER II. 



On the Larva and Pupa of a Straw-coloured Plumed 

 Culex or Gnat. 



Tipula cristallina of De Geer. 

 Chironomus plumicornis of Fabricius. 

 Corethra plumicornis of Stephens. 



Transparency is a quality so essential to the display of 

 the internal organization of living- objects, that many 

 devoid of it are often disregarded, as of comparatively 

 little interest. The object now before us, however, is so 

 remarkably pervious to light, that under the microscope 

 we are enabled to view every part of its interior structure 

 with facility. Indeed, it is diaphanous in such a degree 

 as to render it difficult to be discovered in the waters in 

 which it resides, for it assimilates nearly in colour to 

 them, during the infant part of its larva state. 



