io6 
Ford —The Anatomy of 
there is a certain amount of regularity in the behaviour of 
the different strands. The shaded strands represent the 
bundles of roots, the unshaded ones the bundles of the stem. 
The triangular areas mark the points at which the petioles 
leave the stem. The stem-bundles 
anastomose frequently with each 
other, union between two adjacent 
strands being however generally 
followed by a re-division of the 
single strand which has resulted 
from this union. The roots in the 
young plant do not arise in the 
same manner as in the mature 
Fern, and a definite relation exists 
between the stem, petioles, and 
roots. Kny 1 , in his work on the 
germination and development of 
the Parkeriaceae, states that in the 
young plant a primary root arises 
a little below each of the primary 
leaves. He does not, however, 
describe in any detail the course 
of the steles of the root, stem, and 
petiole in connexion with this 
relation, which seems to be a very 
constant one. In tracing a series 
of sections from the base upwards 
and towards the stem-apex it is 
seen that a young root, which has 
a single vascular strand, and is at 
first quite distinct from the stem, 
gradually approaches the latter 
until the spongy parenchyma of 
the two unite though the root-bundle remains as yet distinct 
and unchanged. Further up the series, some connexion is 
seen to take place between the root-stele lying in the stem 
1 Kny, 1875, p. 48. 
Fig. 1. Illustrating the course 
of the Vascular Bundles in the 
stem of a young Ceratopteris. 
P = petiole with three bundles 
leaving the stem. S ~ stem- 
bundle. R — root-bundle. 
