pf igh =e Bd SI 
AMERICAN NATURALIST. 
Vol. VII.— MAY, 1873.—No. 5. 
CO EDORVOOD OY 
THE WINTER STATE OF OUR DUCKWEEDS. 
BY PROF. T. D. BISCOE. 
In the autumn of 1871, I brought home a bottle full of duck- 
weed (Lemna polyrrhiza) and emptied it into. a tumbler of water 
with a mass of alge gathered at the same time. 
Within a few days the Lemne all turned white and died, and 
the fronds seemed to decay. I kept the algæ in the tumbler all 
winter, adding fresh water as fast as it was diminished by evapora- 
tion. I saw no more of the duckweed till the last of the winter, 
when one day, to my great surprise, there appeared floating on the 
water a group of fronds that were certainly Lemne, and a few days 
after I noticed another frond. What had they grown rom? I 
turned out the water into a basin and found about fifty little disks 
which seemed to answer the description of autumnal or winter 
fronds as described in my “ Gray.” 
My curiosity was excited. How could such things grow into 
Lemnæ? Where was the growing point? Where were the roots 
to start from? What was the internal structure of these regular 
little disks? Should 1 find anything corresponding to buds about 
them? ‘ 
Some of these queries I have answered and oer are sin, un- 
solved. 
I propose to give a short account of my failures wid successes, 
and of the methods of investigation by which I tried to reach the 
knowledge sought ; and hope that my trials may be of service to 
SUD ia 
Entered, according to Act of Con ress, in the year 1873, by the PEABODY ACADEMY OF 
SCIENCE, in the Office of the Lib paren of Congress at Washington. (257) 
17 
AMER. NATURALIST, VOL. VII. 
