iSSg.] Entomology. 455 
the larvae of the various groups of the animal kingdom with 
the results of the study of adults. The following questions 
are among those for which an answer is sought : 
To what extent are larval forms representatives of ances- 
tral stages in the history of animals, and to what extent are 
they adaptations on the part of the larvae, and therefore sec- 
How far is it possible to assign reasons for the larval de- 
partures from ancestral type ? 
Has the larval departure from an ancestral type, where it 
has taken place, occurred in numerous individuals simultan- 
eously, or have the variations appeared in one individual and 
then been transmitted from it to a long line of posterity. 
Have the forms and habits of the adult any direct influence 
on the larvai, or those of the larvae on the adult.? 
Are larvae reliable as a basis of classification. 
Are larvae of any value in teaching the past history of ani- 
Are larvai of any value in teaching relations .? 
In cases where larvae are departures from the ancestral type, 
and therefore secondary, are they of any value in teaching 
past history or present classifications } 
Are larvae more or less variable than adults } 
Are adaptive larval characters inherited by succeeding 
larvae } 
The present paper is the result of the study of the larvs of 
beetles, this group being first selected as showing the great- 
est amount of variation within a single order. As a starting 
point a Campodeoid form is taken. This is the most widely 
distributed, and has frequently been pointed out as the closest 
representative of the ancestral insect living at the pres- 
ent day. Starting with the Campodeoid type the different 
families of beetles have been studied as far as is possible with 
our present knowledge of them. The following are the most 
important points presented by the study of this group. 
1. With the exception of the Campodeoid type of larvs, 
which is found in a number of families, all beetle larvae are 
secondary modifications which have been introduced during 
the larval life of the beetles, and have never been represented 
by any adult features. They are, therefore, of no value m 
teaching the history of beetles except in their larval stages. 
They do not represent ancestral stages. They may, how- 
ever, and frequently do, teach relationship, since the pres- 
ence of a similar larva may indicate a recent r -" — 
2. It is possible, amid the immense variety c 
