DISTRIBUTION 574 
ruption of local life may have caused.” (Scudder.) Probably 
many species were exterminated and many others became 
greatly modified, though little is known as to the relationship 
of the present fauna to the preglacial fauna. “ The glacial 
cold still lingers over the northern part of this continent and 
our present animals are only a remnant of the rich fauna that 
existed in former ages, when the magnolia and the sassafras 
thrived in Greenland.”’ 
Island Faune.—The ability of insects to surmount barriers, 
under favorable circumstances, is strikingly shown in the col- 
onization of oceanic islands. Not a few insects, including 
Vanessa card, have found their way to the isolated island 
of St. Helena. In the Madeira Islands, according to Wollas- 
ton, there are 580 species of Coleoptera, of which 314 are 
known to occur in Europe, while all the rest are closely allied 
to European forms. Subtracting 120 species as having been 
introduced probably or possibly through the agency of man, 
there remain 194 that have been introduced by “ natural ”’ 
means. The rest, 266 species, are endemic, though akin to 
European species. 
The scanty insect fauna of the Galapagos Islands includes 
twenty species of Orthoptera, which have been studied by 
Scudder and by Snodgrass. Five of these are cosmopolitan 
cockroaches, doubtless introduced commercially, and the re- 
maining fifteen are all “ distinctly South and Central American 
in their affinities.’ Three of these fifteen are strong-winged 
species which doubtless arrived by flight from the neighboring 
mainland; indeed, Scudder records a Schistocerca (S. exsul) 
as having been taken at sea two hundred miles off the west 
coast of South America, or nearly half way to the Galapagos 
Islands. Thirteen of the fifteen are endemic, and five are 
apterous or subapterous, while a sixth has an apterous female. 
Apterous insects, noticeably common on wind-swept oceanic 
islands, may have been carried thither on driftwood, though 
?# is more likely that the apterous condition arose on the 
islands, where the better-winged and more venturesome indi- 
