METAMORPHOSES OF INSECTS 45 



to millions, since Leuwerihoeck, the best observer on 

 such subjects, found more than 400,000 of them on the 

 wings of the silk-worm moth, which is comparatively a 

 small insect. 



116. The construction and arrangement of the parts of 

 these scales are very regular and beautiful, their surfa- 

 ces being striated with parallel, and equi-distant lines, 

 the distinct visibility of which, in those from the Pontia 

 brassica, or cabbage-butterfly, is considered as affording an 

 excellent test of the goodness of microscopes. 



117. The forms of these scales as seen by the adjoining 

 figures are exceedingly various, as also their sizes, when 

 magnified by the same power. These differences of 

 form occur not only in the different species, but also on 

 different parts of the wings and body of the same in- 

 sect ; for the surface of the body generally, as well as 

 the legs, and in some species the antennaB, are more or 

 less covered with these scales. These forms are indeed 

 so various on different parts of the same insect, that in 

 the works of that distinguished naturalist, Lyonet, there 

 are six quarto plates nearly covered with the delineations 

 of different forms of these scales found on a moth of the 

 silk-worm tribe, the Bombyx cossus. 



118. The arrangement of these scales upon the wings 

 are in regular transverse lines, the ends of one row lying 

 over the basis of the next, like the shingles on the roof 

 of a house. When these are removed from both sides 

 of the wings of a butterfly, it will be seen that these parts 

 are exceedingly thin and transparent, like the wings of the 

 dragon fly and bee. 



119. Red drops emitted by Butterflies. Several spe- 

 cies of butterflies, just after the time of changing from the 

 chrysalis to the perfect state, or perhaps at that of emer- 

 ging from their place of confinement, emit several drops of 

 a red fluid, resembling blood in appearance. When a 

 great number of these insects have been produced at 



Whence does the genus to which the butterfly belongs derive its name? 

 What is said with respect to down on the wings being feathers? What 

 is said of these scales with respect to their being a test of the goodness 

 of microscopes? What is said of the different forms of these scales? 

 How are they arranged on the wings of the insect ? 



