THE WINTER STATE OF OUR DUCKWEEDS. ` 267 
out over the budlet; and, as the section, Fig. 4, shows, forms the 
cover “ k” of the cavity in which the bud “ b,” Fig. 4, lies. The 
body of the bud, having grown much faster than the membrane, 
has left the latter as the semicircle seen at the base in Fig. 2. The 
same thing is true of the lower membrane which now only forms a 
border to the enlarged roots. 
The books speak of Lemna as a plant entirely destitute of 
leaves, but it seems to me that an exception must be made in the 
case before us, for this membrane on the upper and under sides 
Fig. 56. 
seems to answer in its position and formation to the sheathing 
leaves of the monocotyledons. 
I noticed the peculiar form of the cells of the semicircular lobe 
of the leaf (?) on the upper side of the frond, and made a draw- 
ing of them, Fig. 54, and also a drawing of the same organ in the 
bud state, Fig. 55. It was this peculiar form of cell in the two 
cases which first led me to think that they were the same thing in 
different stages of growth. ‘In Fig. 56 I have presented a surface 
view of the epidermis of the frond, together with the underlying 
cells of the frond. Two of the latter cells are nearly filled with a 
large crystal in each. What is the cause of the brown color of 
Some of the cells of the upper lobe of the leaf as shown in Fig. 
54, while others are clear, I cannot tell. 
EXPLANATION OF PLATE. 
Fig. 1. Winter frond, natural size; surface and profile views. 
