126 INTERNAL ANATOMY OF INSECTS. 



caterpillars of Lepidoptcra they are of the former de- 

 scription, and every grain wears some resemblance to an 

 insect's egg : as the passage in many of these consists of 

 six fleshy parts separated by channels, so the excrement 

 represents six little prisms separated by six channels a . 

 The Aphides all secrete a fluid excrement as sweet as 

 honey, of which the ants are so fond b , which is ejected 

 not only at the anal passage, but, in many, by two little 

 siphonets also above it c . A semi-fluid excrement is pro- 

 duced by some species of Chermes, as that which inhabits 

 the Box, which often comes from the animal in long con- 

 voluted strings resembling vermicelli. Reaumur says its 

 taste is agreeable, much more so than that of manna d . 

 Under this head should be included the abundant spume 

 with which the larva of Cercopis spumaria envelopes it- 

 self*. 



I am, &c. 



a Reaum. i. 143. t. v.f. 9. b VOL. II. p. 88. 



c De Geer iii. 26. d Reaum. iii. 357. t- xxix./. G 10. 



e VOL. II. p. 225. 



