Ophioglossum ( Cheiroglossa ) palmatum , L. 281 
foliar gaps formed later (III), but in this case no strands of a leaf-trace were 
recognized as passing off. A little higher up a second leaf-gap appears on 
the opposite side of the stele, the xylem being thus separated into two 
equal bands, while from the middle of each of them a root-strand is given 
off (IV). It is at this level that the endodermis becomes indefinite, and it is 
not recognizable higher up. Nor is there at any point any indication of an 
internal endodermis. Shortly the first foliar strands are separated from the 
margins of the second gap (V) as two quite distinct strands, widely apart 
from one another in their origin, and showing further divergence as they 
pass outwards (VI, VII). Meanwhile the meristeles of the axis again extend, 
and close the leaf-gaps, so that the ring is reconstituted (VII). Other leaf- 
traces follow after the same plan, though not with any exact or constant 
angle of divergence. The two strands entering a leaf soon divide up 
according to the plan shown for the older leaves (Fig. 2), but naturally the 
branching is here carried out to a less degree. 
A condition is found in the lower region of the old stock above described, 
which may be regarded as a natural consequence of the parenchymatous 
swelling of it for storage purposes. As shown in Fig. 6, the pith becomes 
greatly distended, as compared with Fig. 3 ; the meristeles pass further 
apart, and the stelar condition becomes accordingly disturbed, and less 
readily intelligible. The large pith is traversed by a number of roots. 
Four of these are shown in Fig. 6, but as many as six have been observed. 
The roots are usually triarch, but sometimes diarch. They appear to pass 
into the pith from outside, traversing the foliar gaps. Though this con- 
dition is unusual, if not actually unique among the Pteridophytes, it is 
similar in principle to what is seen in Lycopodium Selago and some other 
species, where the roots traverse the softer middle cortex. In the present 
case all the tissues except the vascular skeleton are soft, and entry into the 
pith is as easy as a course through the cortex, while access to the soil is 
gained through the equally soft basal region of the tuberous stock. 
An examination of the roots which traverse the humus in which the 
plant grows shows the presence of endotrophic mycorrhiza, though not in 
such a profuse development as the habit of the plant might lead one to 
expect. 
Comparing what is seen in the stock of O. palmatum with the type for 
Eu-Ophioglossum , the differences appear such as would be natural in 
a tuberous development of that type, having a saprophytic tendency. The 
general development of the vascular tissue is poor, both as regards quantity 
of xylem and of phloem, especially the latter. The stelar construction is, 
however, fundamentally on the same plan, with its basket-like disposition of 
meristeles round a bulky pith. If the normal system of O. vulgatum 1 be 
imagined as abbreviated and distended the condition would not be unlike 
1 Land Flora, Fig. 256 (5), after Rostowzew. 
