THE INSECT WORLD. Gs 
other, and he demonstrated that in the case of kinds whose 
adults were very unlike in shape, the resemblance of the young 
existed for a certain period, and then anatomical distinctions 
began and progressed until perfection was arrived at. There 
are, therefore, changes inside the egg, and moultings and 
metamorphoses outside, during the life history of most of the 
Articulata. 
Perhaps, when the matter has been more studied, the animal 
kingdom will be classified by observing the nature of the changes 
from the embryo to the adult form, and during the embryonic 
condition, but at present there are some difficulties to be over- 
come, for very similar creatures have different metamorphoses | 
and grades of changes of shape. 
That is to say, there are animals which resemble each other 
so far as their structures and habits are concerned, and which 
go through complete metamorphoses, and others that only have 
to submit to slight changes of shape and structure. The dif- 
ference is most striking, but, nevertheless, when the immature 
forms, and even the adults, are anatomised, the greatest resem- 
blances are detected between them. The beetles—for instance, 
the cockchafer and the stag beetle—are born in a very incomplete 
or embryonic condition. Insects of the order of the Orthoptera 
—the grasshoppers or the earwigs—on the contrary, when they 
come out of their eggs nearly resemble their parents, and they 
do not undergo true metamorphoses. But the beetles and the 
grasshoppers, so. far as the details of their construction are con- 
cerned, do not show any but secondary differences. The beetles 
have greater structural resemblances to the grasshoppers than 
they have to the butterflies, yet they resemble these last in 
their method of development and evolution. Similar peculiarities 
may be detected amongst the Crustacea. The lobster and the 
prawn are closely allied by their similarity of construction; but 
the first hardly undergo a change, whilst the last present three 
forms before reaching the mature beauties of prawn life. 
It would appear—after studying the metamorphoses of the 
Articulata and their skin sheddings, which are really the external 
evidences of an inward transformation, which is not marked by 
a great break or phase in the insect economy—that these inte- 
