20 
INTRODUCTION. 
closely to the Orthoptera, with which they agree in their * 
partial transformations, and active pupae. They form the 
little order Derm after a of Leach, or Euplexoptera of 
Westwood. 
The spider-flies, bird-flies, sheep-tick, &c. (^Hipi^ohoscadce)^ 
which, with Latreille and others, I have retained among the 
Diptera, form the order Hom adopter a of Leach, and the 
English entomologists. 
The May-flies, or case-flies (JPhryganeadcB)^ have been 
separated from the Xeuroptera; and constitute the order 
Trichoptera of Ivirbv. Latreille and most of the natu- 
«/ 
ralists of .the continent of Europe still retain them in 
Xeuroptera, to which they seem properly to belong. 
The TJir{p)S 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 Thysanoptera of Haliday ; but I propose to leave it, 
as Latreille has done, among the Hemiptera. 
The English entomologists separate from Hemiptera the 
cicadas or harvest-flies, lantern-flies, frog-hoppers, plant-lice, 
hark-lice, &c., under the name of Homoptera ; but these 
insects seem too nearly to resemble the true Hemiptera to 
warrant the separation. 
Burmeister, a Prussian naturalist, has subdivided the Xeu¬ 
roptera into the orders Xeuroptera 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 Xeuroptera will be justifiable 
also. 
Objections have often been raised against the study of 
natural history’, and many persons have been discouraged 
fi’om attempting it, on account of the formidable array of 
scientific names and terms which it presents to the 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- 
