1899 | LIFE-HISTORY OF LEMNA MINOR 39 
above this another internodal region (fg. z, c) which is entirely 
expanded as an organ of photosyntax. This function is also 
taken up by expanded portions of the node and basal internode, 
which are not distinguishable from the upper internode. In this 
. Diagram of an adult plant. At the right of the main axis is a flower 
ies its ks J, and carpel extending through the pouch opening. At the left, a 
young plant, ¢, bearing younger plant, ¢, opposite which is a young flower. a, basal 
internode. Be node. X 4 
- Four generations of plants, a, 4, c, d, respectively. e, old flower. f, young 
ia r, root. &, root cap. X 45. 
upper region are three strands of conducting tissue, which in 
many cases were seen to proceed from the single vascular bundle 
that passes from the basal internode through the node. Fre- 
quently this presents the appearance of being one main axial 
bundle with a branch on each side. These conducting tissues 
extend almost to the margin of the frond,’ passing in the upper 
I, 2), oc. 2, obj. 3; X 73 (figs. 9, 12), oc. 4, obj. 3; X 260(fig. 10), oc. 160™™, obj. se 
% §20 (fig. 11), oc- 160™, obj. ts; X 760 (figs. 4, 5, 6, 57, 59), oc. 4, obj. 7; X 8 
(figs. 14-16, 42), oc. 2, obj. gx; X 1375 (figs. > 7, 13, 17-37, 40, 41, 43-56, 58), oc. . 
obj. iss X 2400 (figs. 31, 32, 38, 39), oc. 12, obj. py. 
€ term “frond” is usually applied to rile entire plant. The use of the term 
