and Helminthostachys zeylanica. 
4i 
Morphology and Anatomy of the young Sporophyte 1 . 
Two young plants still attached to prothalli are represented 
in Figs. 61 and 62. In the former the first leaf has fully 
expanded, and is seen to have a ternate lamina borne on 
a long, slender leaf-stalk. Close to the insertion of the pri- 
mary root the foot is enclosed in the prothallus. An inter- 
node of some length occurs below the separation of the first 
leaf, and just above this the second root (r) has emerged. 
The second leaf is about to break through the sheath of the 
primary leaf. 
The plant shown in Fig. 62 is older, the second leaf having 
expanded, while the third root, which corresponds to the leaf 
still enclosed in the bud, has commenced to elongate. The 
oldest plant found attached to a prothallus bore three 
.expanded leaves. All the young plants were dorsiventral 
even in the first internodes, which are usually vertical : the 
leaves are given off from one side of the axis and the roots 
from the other. Farmer and Freeman have recently shown that 
no definite relation exists between leaf and root in the older 
plants. In the young plant there is a correspondence in number 
between these organs, the primary root corresponding to the 
primary leaf, and a root arising from the stem just below each 
succeeding leaf-trace. The root attains a considerable length 
before the leaf, below which it arises, commences to grow. 
Even in the young plant, however, it arises from the stem- 
stele, and not from the leaf-trace. The constant relation, 
which for a time exists between the leaf and root, while 
doubtless important physiologically, does not appear to 
possess any great morphological importance. 
The structure of the mature plant * of Helminthostachys 
has recently been fully investigated by Farmer and Freeman 2 , 
so that the observations made on the plants attached to pro- 
thalli need only be briefly described. This will supplement 
1 I am indebted to Mr. Gwynne-Vaughan for assistance and advice in the study 
of the young plants. 
a Annals of Botany, vol. xiii, p. 421. 
