PREFACE. 
V 
comparative study of the various methods of specialization 
has been beyond the reach of any but the most advanced 
scholars. 
The principal features of the method of notation of wing- 
veins proposed by Josef Redtenbacher has been adopted. 
But as the writer’s views regarding the structure of the 
wings of primitive insects are very different from those 
of Redtenbacher, the nomenclature proposed in this book is 
to a great extent original. The chief point of difference 
arises from the belief by the present writer that veins IV 
and VI do not exist in the Lepidoptera, Diptera, and 
Hymenoptera; and that, in those orders where they do exist, 
they are secondary developments. The reasons for this be. 
lief are set forth at length in my essay on Evolution and 
Taxonomy. 
In this essay there was proposed a new classification of 
the Lepidoptera, which was the result of an effort to work 
out the pliylogeny of the divisions of this order. This classi¬ 
fication has been further elaborated in the present work. In 
the other orders but few changes have been made from the 
more generally accepted classifications. It is more than 
probable however, that when the taxonomic principles upon 
which this classification of the Lepidoptera is based are ap¬ 
plied to the classification of the other orders radical changes 
will be found to be necessary. 
A serious obstacle to the popularization of Natural His¬ 
tory is the technical names that it is necessary to use. In 
order to reduce this difficulty to a minimum the pronuncia¬ 
tion of all of the Latin terms used has been indicated, by 
dividing each into syllables and marking the accented 
syllable. In doing this the well-established rules for the 
division of Latin words into syllables have been followed. 
It seems necessary to state this fact in order to account for 
differences which exist between the pronunciations given 
here and some of those in certain large dictionaries recently 
published in this country. 
