MEMOIES OF THE l^ATlOlsAL ACADEMY OF SCIEi^CES. 
51 
MELANISM IN THE WHITE AND ROOKY MOUNTAIN AND rACIFIC COAST MOUNTAIN REGIONS. 
Without at present entering into the discussion of the general causes of melanism, wo will 
draw attention to such cases as have fallen under our notice in the present group. 
rt seems generally recognized, however, that melanism is due to elevation (not necessarily a 
high latitude) united with an excessively humid or wet climate. We have such elevated areas over 
Avhich the rainfall is excessive in the AVhite Mountains, in the Adiroudacks, in the mountains of 
British America, the Cascade Range and its spurs in British Columbia, Washington, and Oregon, 
and in the elevated portions of the Sierra Nevada and of the Rocky iVtountains, with their subordi- 
nate ranges and spurs. In such a cool and moist climate we also have much cloudy weather and 
far less direct sunlight than on the drier and more sunny lowlands. This does not exclude the 
fact that melanism may occur in a low and wet region, as the west coast of Africa. 
Mrs. Slosson, who has spent numerous summei's in Franconia, N. H., and has had wide 
experience in collecting Lepidoptera in that region, as well us in Florida, informs me that it is 
almost invariably the case that the White Mountain moths are darker and richer in hue than 
southern individuals of the same species. 
^ The following facts bear on this point: 
“But it is also a known fact that many species of animals, especially of insects, which are 
found at a high level on mountains have a darker coloring than their allies at a lower level. Thus 
there are remarkably dark species and varieties of beetles occurring at high levels.” (EimeFs 
Organic Evolution, p. 9d.) 
The late Dr. Weinland, who lived some years in the United States, remarks, as quoted by 
Eimer, “that darker pigment is always produced on mountains, as in Vipera prester^ the Black 
Mountain variety of Vipera herm^ as in the black rattlesnake of the White Mountains in North 
America” (Ibid., p. 98). 
Eimer thinks only two causes, apart from moisture, aid in the production of dark hues in Alj)ine 
animals, i. e., “ either light or decreased atmovspheric pressure,” But is not the cloudiness and 
dullness of the skies about mountain summits, i. c., the absence of sunlight as compared with the 
bright sunny days of the lowlands, sufficient, with moisture, to account for the increase in dark 
pigment? Though, to be sure, the heat and moisture of the west coast of Africa cause the greatest, 
extreme of melanism in the negro races. 
Cases of melanotic forms^ both in the Eochy Mountains and on the himidj cool portions of the Pacific 
Coastj and- on the Atlantic Coast regions, 
Gluphisia severa var. slossonim (White Mountains). 
Ichthyura brucei var. multuoma (Oregon and Washington). 
Pheosia dimLdiata var, portlandia (Oregon and Washington). 
Notodonta stragula var. paciiica (California), 
Heterocam])a guttivitta. Franconia, N. H. 
Cerura multiscripta. In the Northeastern States. 
It should be noted that Cerura scitiscripta is represented in New England by the dark form 
(7. multiscripta. 
It is greatly to be desired that hereafter collectors working in the Rocky Mountain regions, as 
well as anywhere in the Campestrian region, including the Pacific Coast, should carefully state on 
their labels the exact locality, with date (at least the month), of their captures, 
VII.— ON THE PHYLOGENY OR CLASSIFICATION OF THE LEPIDOPTERA. 
It hardly need be said that the classification of the Lepidoptera is in a very unsatisfactory 
state. This is due largely to the fact that the group is so homogeneous, that the habits and 
environment of the species are so uniform, and that the adaptive modem characters have hidden 
the slight primitive or ancestral characters which crop out in certain forms; hence the phylogeny 
of the order is difficult to unravel. It is now perhaps generally supposed that the Lepidoptera 
have originated from the Trichoptera, or from forms very much like them, the most generalized 
Tineina being closely similar to the caddis fiies, though we shall endeavor to show that this view" 
