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‘plains below, and that they would be just as true Bryonie as those of the present 
—the result of the influence of climate on an impressionable organism, and the 
power of that organism to accommodate itself to altered conditions. 
Now, then, let us return to our poor old friend Semidea, who has been having 
such a weary time of it on top of Mount Washington, for the last eighty thousand 
years. J do not know the form of Chionobas that flies on the plains of New 
Hampshire. Iam dealing with one of the laws of nature that controls life, a far 
more reliable guide to correct conclusions, than the changeable external appear- 
ance of insects. But whatever they may be like, or by whatever name they may 
be called, 1 am quite confident, that upon investigation one of them will be 
found to stand in the same relation to Semidca that Napi does to Bryoniaw, and 
will be found capable of pushing its way up Mount Washington and to be modi- 
fied by the changed conditions, and by the time it has established itself on the 
top it has become true Semidea; so that if at any time Semidea had been obliterated 
from Mount Washington by the severity of the conditions, and it would seem 
little short of a miracle if it never has been, its place could yet be filled from 
below. 
Then there is Semidea in the Mountains of Colorado. The Chionobas of the 
Colorado plains, will undoubtedly be different-looking from those of New Hamp- 
shire and discerned by bearing different names, and from one of them the Semideas 
have come which are found on tbe mountains; the same principle governing 
one as the other. We turn to Labrador and the same principle is at work there, 
only the conditions for the production of Semidea are obtained without the neces- 
sity for the elevation. So that from Labrador within the Arctic circle. to Long’s 
Peak, Colorado, an unbroken chain of that species extends across the 2,800 miles 
that lie between, every link of which may differ somewhat from the one next 
to it, according to the conditions in which it lives,and be entitled to a distin- 
guishing name, yet all united by the laws of consanguinity. At these three points, 
Labrador, Mount Washington and Long’s Peak, Colorado, the conditions being the 
same, like results are produced and Semidea is the natural outeome. And according 
to Mr. Edwards, when specimens are brought from these widely separated locali- 
ties and compared, they are not known io differ by a scale or a hair. . I see that 
Mr. Scudder does not consider the Labrador form quite the same as the others, 
if so it would indicate that the conditions are not quite identical. 
Mr. Edwards inform us that the Satyrinz are a very numerous family, with 
many genera, these having numerous species, which I take as an indication that 
they are sensitive to external influences and readily modified thereby, and pro- 
bably a full series might exhibit the gradations to be slight. 
This, then, is the view I take of the way in which Arctic forms have been 
originated and perpetuated, and the principle at work in producing them is 
that which has been so carefully elaborated with such a wealth of illustration 
and knowledge of facts by Wallace in his Island Life; only he calls the forms 
produced by changed conditions “species” instead of varieties of a species, a 
mode of using the term that is ever liable to lead to confusion and misun- 
derstanding. 
