MEMOIR OF ARISTOTLE. Ill 
such. His idea of Hemiptera seems taken solely 
from the Cicada or Tettix; but the manner in which 
he expresses himself concerning it, as having no 
mouth, but furnished instead with a linguiform or- 
gan resembling the proboscis of Diptera, proves 
that he regarded it as the type of a distinct group. 
Since he considers the saltatorious Orlhoptera as 
forming such a group, it is probable that he included 
the cursorious ones with the Neuroptera in his ma- 
jor a section of Tetraptera; and the resemblance of 
many of the Mantidce to the Neuroptera is so great, 
that this mistake would not be wonderful. His di- 
vision of the Diptera is quite artificial. 
“ How far Aristotle’s ideas with regard to genera 
and species attained to any degree of precision, is 
not easily ascertained : in other respects, his know- 
ledge of insects was more evident. As to their ana- 
tomy, he observes that their body is usually divided 
into three primary segments — head, trunk, and ab- 
domen ; that they have an. intestinal canal — in some 
straight and simple, in others contorted — extending 
from the mouth to the anus ; that the Orthoptera 
have a ventricle or gizzard. lie had noticed the 
drums of Cicada, and that the males only are vocal. 
Other instances of the accurate observation of this 
great man might be adduced, but enough has been 
said to justify the above encomiums. His principal 
error was that of equivocal generation 
* Introduction to Entomology by Kirby and Spence, 
Vol. iv. p. 433-434 
