45° 
The Ohio Naturalist. 
[Vol. VI, No. 3, 
disappearing. And last, but not least, the influence on general 
health is a grave consideration. 
But to come back to mollusks. Of late years, the shell and 
pearl hunters have come, and killed our mussels, where there still 
were any, by the millions, in rivers and creeks. In many places 
they have been nearly exterminated, and only the naturalists 
deplore the fact. 
What can we do? When Hebra, the great dermatologist at 
the University of Vienna, presenting to his students a peculiarly 
malignant case of a skin disease, asked the practicing student 
what could be done for the patient, and the young doctor could 
only shake his head and stand silent, “well, we will have him 
photographed,” Professor Hebra would say. This is about our 
position. In the first place, we can record the fact, and deplore 
it. In the second place, we can take a careful inventory of what 
is still left. And that we should do, energetically: work up the 
muollsca in the rivers, creeks, springs, swamps, in the forests 
and copses left, and have them in our records and collections, 
for future generations to look at. In the third place, we 
might find some creek here or there, or part of such, preserve it 
in as natural conditions as possible, eventually with additional 
ponds, and try to preserve in it, and on its banks, such mollusks 
as are threatened with extermination. This sounds utterly 
fantastic! and yet the time may come when such a plan may be 
considered. 
And in the fourth place, and above all, let us unite forces 
with government officials, and anybody who will try to put an 
end to the reckless deforestation of our land, and the reckless 
contamination of our waters with factory and city refuse. 
Already it is much too late, but still much can be accomplished. 
I believe it is not below the dignity of the Academy and its 
members to direct their attention to these eminently important 
tasks and to do all in their power to ])romote them. 
I know well that I go far beyond my scope with these last 
remarks, but these matters were so much no my mind that I 
could not help at least touching them, and I hope to be excused 
for doing so, even if the topic “mollusks” is only incidental 
to them. 
ADDITIONAL OBSERVATIONS ON SELF-PRUNING. 
John H. Schaffner. 
In 1901, Mr. Tyler and the writer published some notes, in 
The Ohio Natur.\list, on the self-pruning habits of a consid- 
erable number of trees and shrubs. The list has been extended 
from time to time by the writer, the work being confined neces- 
sarily to the common woody plants of our region. It is gratify- 
