MICROSCOPIC OBJECTS. Ill 



(5.) " The Tinea vestianella, or Clothes Moth.— These 

 small brown moths possess very delicate and unique 

 scales, requiring some tact in the management of the 

 illumination to resolve their lines distinctly. I should 

 observe that it is the small feathers only, from the 

 under side of the wing, that must be considered as tests ; 

 the others are easy. This is a^ favourite object with 

 some who exliibit it as the standard of excellence. I do 

 not consider it very difficult, though it must be admitted 

 that to bring out the lines sharp and clean requires an 

 excellent instrument." 



(6.) The scales of the Lasciocampa Quercus (Bombyx 

 Quercus) are stated by some observers to have triple lines, 

 the centre one much stronger than those on each side. 

 The scales for these observations must be taken from the 

 margin of the under w^ing of the male moth. 



(7.) "PontiaBrassica. — The pale slender double-headed 

 feathers, about one-eightieth of an inch long, having brush- 

 like appendages at their insertion, obtained from some 

 portions of the wing of the large Cabbage Butterfly, afford 

 an excellent criterion of the goodness of a microscope. 

 Some connoisseurs prefer them to all others, and form 

 an accurate judgment of an instrument by the manner in 

 which it demonstrates this single object. They are 

 easily detached from the wing by the point X)f a quill, but 

 must be gently handled, for, like many others, they are 

 soon mutilated ; indeed I have seldom seen them perfect 

 in the ordinary sliders. Those specimens which are easily 

 resolved are readily distinguished, being short, broads. 



