with special reference to the occurrence of Amuitosis, etc. 879 
Fig. 3. Edge of a transverse section through a root near the apex 
to show the relatively large size of the nucleus (r.h.n.) in a cell which 
is destined to form a root hair. One layer of dying root-cap tissue (r.c.) 
remains outside the piliferous layer (p./.). The base of the root-hair 
cell is enclosed in a jacket of small cells (j.). (x 318.) 
Fig. 4. Edge of a transverse section between 1 and 2 cms. from 
the apex of a root for comparison with Fig. 3 (on a smaller scale). No 
root-cap tissue is present, and one cell of the piliferous layer (p.l.) has 
begun to grow out into a root hair. The jacket of cells (j.) at the base 
of the root hair has become more conspicuous. (x 198.) 
Fig. 5. Small part of a longitudinal section of an adventitious 
root embedded in stem tissue, to show multinucleate cells in the root- 
cap (7.c.) and in the stem cortex (c.). The arrow indicates the 
direction of the root-apex. S.=space between root-cap and stem tissue 
which contains nuclei and other remains of disintegrating cells (d.). 
(x 318.) 
Prate IX. 
Stratiotes aloides L. 
Fig. 6. Part of the stele from a longitudinal section of a young 
adventitious root of a plant collected August 11th, 1910, passing through 
two embryonic vessels (v.) and their associated parenchyma cells («.p.), 
many of which have lobed nuclei. In the cells marked y, y’, x and 2, 
different stages of amitosis can be observed, while the cell marked a is 
also an example of a binucleate cell. Drawn from three successive 
microtome sections. (x 318.) 
Fig. 7a. Cells of the outer cortex containing more than one 
nucleus, from a transverse section of a young adventitious root. 
x 318. 
ie 7b. A cell of the outer cortex containing a lobed nucleus from 
a longitudinal section of an adventitious root. (x 318.) 
Figs. 8a and 6. A binucleate cell and a lobed nucleus from a 
longitudinal section of the base of a leaf. (x 318.) 
Figs. 9a—d. Parts of the stele from a transverse hand section of a 
young adventitious root of a plant collected August 11th, 1910, showing 
lobed nuclei in the pericycle and stelar parenchyma, and, in 9¢, a case 
of actual division of the nucleus in a xylem parenchyma cell. (x 900.) 
(c. = cortex; e.=endodermis; p.=pericycle; px. =? protoxylem ; 
v. =metaxylem vessel; s.t.=%sieve tube.) 
Fig. 9e. Two lobed nuclei from a transverse section of the stele of 
a young root, showing the lobing in greater detail. (x 900.) 
