20 
INTRODUCTION. 
closely to the Orthoptera, with which they agree in their 
partial transformations, and active pupae. They form the 
little order Dermaftera of Leach, or Euplexoptera of 
Westwood. 
The spider-flies, bird-flies, sheep-tick, &c. ( Hippoboscadce ), 
which, with Latreille and others, I have retained among the 
Diptera, form the order Homaloptera of Leach, and the 
English entomologists. 
The May-flies, or case-flies ( Phryganeadce ), have been 
separated from the Neuroptera ; and constitute the order 
Trichoptera of Kirby. Latreille and most of the natu- 
ralists of the continent of Europe still retain them in 
Neuroptera, to which they seem properly to belong. 
The Thrips tribe consists of minute insects more closely 
allied to Hemiptera than to any other order, but resembling 
in some respects the Orthoptera also. It forms the little 
order Thysaxoftera of Hahday ; but I propose to leave it, 
as Latreille has done, among the Hemiptera. 
The English entomologists separate from Hemiptera the 
cicadas or harvest-flics, lantern-flies, frog-hoppers, plant-lice, 
bark-lice, &c., under the name of IIomoptera ; but these 
insects seem too nearly to resemble the true Hemiptera to 
warrant the separation. 
Burmeister, a Prussian naturalist, has subdivided the Neu- 
roptera into the orders Neuroptera and Dictyotoptera, 
the latter to include the species which undergo only a partial 
transformation. If Hemiptera is to be subdivided, as above 
mentioned, then this division of Neuroptera will be justifiable 
also. 
Objections have often been raised against the study of 
natural history, and many persons have been discouraged 
from attempting it, on account of the formidable array of 
scientific names and terms which it presents to tin; beginner ; 
and some men of mean and contracted minds have made 
themselves merry at the expense of naturalists, and have 
sought to bring the writings of the latter into contempt, be- 
