7# HISTORY OF 



head, they are found, in the butterfly, to take a 

 direct contrary course, and to circulate from the 

 head to the tail ; so that the caterpillar may be 

 considered as the embryo animal, in which, as we 

 have formerly seen, the circulation is carried on 

 differently from what it is in animals when ex- 

 cluded. 



But leaving the other parts of the butterfly, let 

 us turn our attention particularly to the head. 

 The eyes of butterflies have not all the same 

 form ; for in some they are large, in others small ; 

 in some they are the larger portion of a sphere, 

 in others they are but a small part of it, and just 

 appearing from the head. In all of them, how- 

 ever, the outward coat has a lustre, in which may 

 be discovered the various colours of the rainbow. 

 When examined a little closely, it will be found 

 to have the appearance of a multiplying glass ; 

 having a great number of sides, or facets, in the 

 manner of a brilliant cut diamond. In this par- 

 ticular, the eye of the butterfly, and of most other 

 insects, entirely correspond ; and Leuwenhoek 

 pretends, there are above six thousand facets on 

 the cornea of a flea. These animals, therefore, 

 see not only with great clearness, but view every 

 object multiplied in a surprising manner. Puget 

 adapted the cornea of a flea in such a position, 

 as to see objects through it by the means of 

 a microscope ; and nothing could exceed the 

 strangeness of its representations : a soldier, who 

 was seen through it, appeared like an army of 

 pigmies ; for while it multiplied, it also diminished 

 the object : the arch of a bridge exhibited a spec- 



