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1878.) Phosphorescent Insects. Their Metamorphoses. 355 
the inquirer to follow them throughout their developmental 
career to ultimate perfection in the imago; and in them also may 
be seen to commence anew the life cycle dating from the deposi- 
tion of ova. This rare privilege of tracing insect metamorphosis 
is not afforded however, even under the most favorable circum- 
stances, without great risk of self deception on the part of the 
investigator. 
Of phosphorescent Lampyride in the south-western part of the 
Atlantic district I am acquainted with eight species; two of these 
have apterous females, which are also distinguished by other 
peculiarities. In this article I shall assume their origin from a 
common type, which by a series of progressive and retrograde 
` steps have given rise to their present forms. 
Buffon’s assertion that “nothing in nature is so permanent as | 
type,” is well sustained in the known tendency of both plants and 
animals, when not influenced by extraneous causes, to return to 
an original model; while on the other hand this very inclination 
to resume a certain form implies a capability of change. 
. “Whenever,” says Humboldt, “a new element develops itself 
in the feelings of mankind, it may almost invariably be traced to 
an earlier, deep-seated, latent germ.” What this great writer said 
of the emotional nature, will probably apply with equal force to 
the development of physical structures and functions. The 
capability of adapting or evolving these is the “ deep-seated, latent 
germ ” which is a positive power residing in animal forms, only 
awaiting the given conditions of its action to produce apparent 
anomalies, and in some instances masked representatives of seem- 
ingly extinct races, constituting a reversion to their primitive type. 
This assumption of new powers is witnessed in the metamor- 
Phosis of any insect, and has led to a close scrutiny of life in its 
earlier or embryonic forms with a view to discover whether all 
the parts of the imago are present in the earlier period; many 
students of nature, perceiving the impossibility of effects without 
something more definite than a name for a cause, have thrown 
great light upon the subject. 
Oken illustrates the gradual elevation in the scale of powers in 
the articulata by the metamorphosis of the Lepidoptera, which he 
Says are born as worms, represent the crustacea in the pupa stage 
and finally attain true insect perfection in the imago. 
Beginning at the lowest te of animal perfection as assumed _ 
VOL, XIT—NO VI. 
