266 THE WINTER STATE OF OUR DUCKWEEDS. 
Fig. 13 shows the three roots at once, though with the middle 
one out of focus. The left hand part of this section is a puzzle 
to me that I am not sure I have rightly solved. Till I came to it 
I did not suppose there was any membrane on the lower side like 
“z” In every other section, out of forty, perhaps, that ran through 
that neighborhood, there was no projection of the lower membrane 
toward the left, but the tissue passed continuously from the roots 
round into the base of the upper membrane, as in Figs. 10, 11, 12. 
I think there may be a narrow lappet or lobe of the lower mem- 
brane at’ just this part, while below the tissue may be as in the 
other sections. I do not think that the part marked ‘“‘ œ” is part 
of the budlet, but of the bud. 
Now to take one step more: has the budlet the beginning of a 
budlet of the next generation? Yes, at the point “ e,” Fig. 14, 
there is a slight protuberance just about where the upper mem- 
brane “ a,” Fig. 14, comes to the edge of the budlet. And this is 
what will grow into first the budlet, then the bud, and finally the 
frond. 
When the budlet was dissected out and examined with a vr 
(Hartnack’s No. 10), the protuberance showed nothing but a group 
of half a dozen to a dozen cells all alike with no sign of any organ 
of any sort. This then was the growing point which I set out to 
find. Now how are the different parts of the frond produced from 
it? As the first stage we have the budlet: it differs from the’ 
growing point only in this that a ridge or lappet has been formed 
on the upper and under surface, which in the sections shows as 
two horns as “a” and “ n,” Fig. 12. These two ridges are really 
one continuous ridge as I could see when rolling a free budlet over 
_ and over. It can be traced from “e,” Fig. 14,in a slanting curved 
line to the back of the budlet near its tip, then down the thickness 
of the budlet till it joins the ridge of the under side. As our next 
step, we see in the bud our ridge grown into those two membranes 
(as we have called them) which a careful examination shows to be 
still continuous at the back edge of ‘the bud about as far out as 
the point “ p,” Fig. 7. Also three roots, Figs. 7, 10, 11, 12, have 
made their appearance near and in the base of the lower part of 
membrane. Also the tissue of the bud is preparing for the 
five or six veins that the frond is to possess, and the stem pos- 
-sesses a single fibre of spiral cells. Now, lastly, what more do we - 
find in the frond? The edge “ d,” of Figs. 14 and 10, has grown 
