-BRIEFER ARTICLES. 
Bark within a tree trunk.—The accompanying photograph is from 
a section of an elm tree about eighty years old, grown at Oberlin, 
Ohio. Some forty years ago, by an accident of some kind, the trunk 
was split down the entire side and the inner parts rotted away. The — 
split was gradually closed by growth and the two opposite sides folded 
inwards, each side covered with bark, until the result was reached as 
seen in the photograph. The two sides produced such a pressure a 
to obliterate the bark at the line of contact, and a few years more would : 
doubtless have closed the wound with a continuous cambium. 
When cut down the bark seemed as vigorous and nearly as thick 
within the trunk, where it must have been quite dark, as on the outside 
of the tree. 
The section is preserved in Oberlin College museum.—F. D- 
KELSEY, Oberlin, Ohio. 
54 Ue 
