22 
ORIGIN OF LIFE IN AMERICA 
have survived the Glacial Epoch in Greenland, yet several 
authors who have written on the lepidopterous fauna of that 
country maintain that the theory of a former land bridge 
with Europe and North America is quite consistent with the 
facts of distribution. Mr. Petersen,* for example, concludes 
from his studies that land connections in high northern lati¬ 
tudes enabled certain arctic butterflies and moths to spread 
from a polar centre to Europe and North America. After 
alluding to a large number of moths common to Canada and 
Europe, Mr. Girard f emphasises the significance of this fact 
as indicating the former existence of a land bridge between 
North America, Greenland and Europe. 
Although no butterflies occur in Iceland, Coleas nastes, 
Argynnis chariclea and A. polaris are known even from the 
barest and most exposed districts of Greenland, where 
nothing but Dryas octopetala and some slender grasses grow. 
These species have a wide range in boreal America, Europe 
and Asia, but of the nine butterflies known from the arctic 
American archipelago five are European, while only two are 
met with in Asia, according to Dr. Pagenstecher. Many 
striking examples, showing the relationship between Green¬ 
land and the neighbouring continents occur among the moths, 
especially among the Noctuidae. Anarta melanopa inhabits 
only Colorado, the White Mountains, Labrador, Scandinavia, 
Scotland and the Alps. Anarta leucocycla and A. lapponica 
are found in Labrador, Greenland and Scandinavia. Mr. 
Grote £ alludes to no less than twenty-eight other Noctuids 
that are common to Europe and North America, even ex¬ 
cluding those met with in Labrador or circumpolar species. 
All these facts tell in favour of the view I have endeavoured 
to elucidate. 
No matter what group of terrestrial invertebrates we 
choose, similar close relationships may be discovered between 
American and European species, which cannot be explained 
by the assumption of a former land connection across Bering 
* Petersen, W., “ Lepidopteren-fauna d. arkt. Gebietes, p. 44. 
f Girard, Maurice, “ L’Entomologie de l’Amerique du Nord,” 
p. 287. 
t Grote, A., “Noctuidae of North America,” p. 313. 
