1889 .] 
167 
[Garman. 
ficient test of good species, then a multitude of forms that are now 
only varieties may be turned into good species by burning the for- 
ests in alternate vallej’S on the sides of this mountain range. 
We further learn that the divergence of these forms is not nec- 
essarily dependent on exposure to different environments ; for the 
climate, rainfall, and other physical conditions of the valleys on 
one side of the mountain range are the same, and the vegetation, 
with the birds, insects, reptiles and mammals, in some of these 
valleys is identical, though the molluscan species are quite distinct. 
In some of these cases where the environment is the same, the 
habits of feeding have changed, which shows that diversity of sue- 
tude 1 of natural selection, and of stimulation, does not necessarily 
depend on exposure to different environments. 
That divergent evolution, through the influence of diversity of 
suetude, natural selection, or any other principle, cannot take 
place without the independent generation of the diverging forms, 
is indicated by the fact that, in forms that are closely allied and 
liable to cross, divergence is measured by the degree of geographi- 
cal segregation ; while between contrasted groups, that are pre- 
sumably held apart by mutual sterility, aided perhaps by dissimilar 
habits of feeding and by sexual instincts, the widest divergence is 
often presented by forms inhabiting the same valley. 
This paper was discussed by Professors Hyatt and Putnam, Mr. 
S. H. Scudder and the Secretary. 
Dr. D. F. Lincoln then spoke of the surface geology of the- Mid- 
dlesex Fells. 
General Meeting, January 16, 1889. 
Prof. Alpheus Hyatt, in the chair. 
The following papers were read : — 
A LARGE CARP AND ITS HISTORY. 
BY SAMUEL GARMAN. 
The first of the letters copied below was placed in my hands by 
Mr. William Hapgood, to whom it had been sent with a box con- 
taining fins, bones and scales of the fish. The letter was written to 
1 Under “suetude” I include use, disuse, and effort. 
