81 
vation, some portions of it having, unfortunately, been badly 
damaged by insect depredations. It contains, besides his own 
collections in the region covered by his book, many specimens 
from Schweinitz, Rafinesque, Torrey, Oakes and Muhlenberg, and 
from his colleagues Drs. Baldwin, Macbride and Mr. Gourdin. 
The representation of material from Muhlenberg is probably 
More extensive than in any other collection in America, and this 
is a most important circumstance, because Muhlenberg’s own her- 
barium, in charge of the American Philosophical Society at Phila- 
delphia, is in very bad order, imperfectly preserved and not very 
easily consulted. I found that a very large number of the species 
of Muhlenberg, first published by Willdenow in his “ Species Plan- 
tarium” and « Enumeratio,” are represented by authentic speci- 
mens in the Elliott herbarium. Inasmuch as the only other 
considerable number of them is to be found in Willdenow’s herba- 
rium at Berlin, we have here an easy and in most cases satisfactory 
method of verifying the original descriptions. 
The herbarium is in charge of Dr. G. E. Manigault, to whom 
I am indebted for much courtesy, and who greatly facilitated my 
studies. N. L. Britton, 
Leliotropism of Cassia Marilandica.—Several times during my 
work in Alabama I had opportunity to note the remarkable 
heliotropism of Cassia Marilandica. The plant is very common in 
what is known as the black prairie soil of the State. The observa- 
tions were made on plants one to two feet in height which had 
not yet produced flower buds. At this time the foliage is very. 
luxuriant, and the lower leaves being quite long and the young 
nes rather crowded on the stem tend to form a loose and broad 
rosette. During sunny days this rosette always faces the sun and. 
8° strong is the heliotropism that the lower leaves are drawn 
slightly toward the center, making the rosette much more compact.’ 
On cloudy days and during the night the plants are normal, but 
during the day when the sun is out the rosette is formed and 
turned so that it faces directly toward the sun, following it through 
the day. Where the plants are numerous they present a very 
beautiful and striking picture, especially during the morning and oS 
‘vening hours, when the angle of divergence is strongest because 
of the low position of the sun. GrorcE F, ATKINSON. — 
