A FEW WORDS ABOUT MOTHS. 227 
The study of the transformations of the moths is also of 
great importance to one who would acquaint himself with the 
questions concerning the growth and metamorphosis and ori- 
gin of animals. We should remember that the-very words 
“metamorphosis” and “transformation,” now so generally ap- 
plied to other groups of animals and used in philosophical 
botany, were first suggested by those who observed that 
the moth and butterfly attain their maturity only by passing 
through wonderful changes of form and modes of life. 
The knowledge of the fact that all animals pass through 
some sort of a metamorphosis is very recent in physiology. 
Moreover the fact that these morphological eras in the life 
of an individual animal accord most unerringly with the gra- 
dation of forms in the type of which it is a member, was the 
discovery of the eminent physiologist Von Baer. Up to this 
time the true significance of the luxuriance and diversity of 
larval forms had never seriously engaged the attention of 
systematists in entomology. 
What can possibly be the meaning of all this putting on 
and taking off of caterpillar habilaments, or in other words, 
the process of moulting, with the frequent changes in orna- 
mentation, and the seeming fastidiousness and queer fancies 
and strange conceits of these young and giddy insects seem 
hidden and mysterious to human observation. Indeed, few 
care to spend the time and trouble necessary to observe the 
insect through its transformations; and that done, if only 
the larva of the perfect insect can be identified and its 
form sketched how much was gained! A truthful and cir- 
cumstantial biography in all its relations of a single insect 
has yet to be written. 
We should also apply our knowledge of the larval forms 
of insects to the details of their classification into families and 
genera, constantly collating our knowledge of the early 
stages with the structural relations that accompany them in . 
the perfect state. 
The simple form of the caterpillar seems to be a concen- 
