104 
IOWA ACADEMY OF SCIENCES. 
Now, the ‘‘ closet-naturalist” has done abundant harm in this 
as in other branches of science. Too remote, often, from the 
phenomena under discussion, or too dainty to soil his fingers 
with the toil and the exposure of field-work, he has passed 
judgment upon the habits of forms which he knew only from 
material submitted by mail; or still worse, he has taken 
the work of others and, not appreciating the significance of the 
facts so borrowed, has distorted them to do menial service 
in the encouragement of some pet notion. 
In the particular case in hand, no distinction has been made 
between the habits of the “depauperate” varieties and the 
larger types of the same species, and too often the habits of one 
species have been confused with those of another, of the same 
genus, or even family, — a mistake most frequently made with 
the Succineas. Again, the universality of certain species, — 
their adaptability to varying conditions, — has been overlooked. 
Zonitoides minusculus, Bifldaria pentodon, B. contracta, Succinea 
avara, S. obliqua, etc., frequently occur in low places, — and then 
often in great numbers, — but they are also found scattered over 
comparatively dry hillsides at considerable altitudes, — and 
some of these species in such places develop the “depauper- 
ate ’ ’ type, — that is, they average smaller in size. 
To show the preponderance of strictly terrestrial forms in 
the loess, the writer calls attention to the fact that in the 
collections made last June, at Natchez and Vicksburg, Miss., 
and numbering over thirty species and nearly 4,000 specimens, 
there is not a single aquatic form. And, furthermore, every 
species which was collected in the loess of that region has been 
found, by the writer, living upon the high bluffs and hills in 
and near Natchez, or upon hillsides at considerable elevations 
in other parts of the south, notably in northern Alabama, 
Georgia, and Tennessee.* At Natches, the most common living 
species is Succmea grosvenorii, and this crept upon the bare 
surfaces of the loess clay which, at the time of the writer’s 
visit, had been baked by the hot summer sun of the south, 
during a period of drouth lasting more than six weeks. More- 
over, several scores of specimens which had been carried about 
in the sun all day long in a box containing loess dust, and hence 
is also a sig’nificant fact that of all the living species found on the hills and 
bluffs of Natchez, only two Leuchochila fallax and Polygyra texana were found in the 
loess of the region, only a single specimen of the first and two of the second were not 
collected in the loess of that region. The former is not uncommon in the loess of the 
north, while the latter is not known from the loess, at least to the writer. 
