Phy lloglossu m Drummondii , Kunze. 319 
for this reason that a description of the best differentiated plant avail- 
able is given first. 
The plant in question is shown in Fig. 2, A. It bears on one side 
a large new tuber above which is situated a leaf, si, somewhat shorter 
than the normal leaves of the plant (see p. 326). On the opposite side, 
two small protuberances may be distinguished, one of which represents 
an abortive tuber, t' , the other, rl, a much reduced leaf. The fact that 
there is in this plant an attempt to form a second new tuber will be 
dealt with later (p. 328) ; the importance of the plant in the present con- 
nexion lies in the anatomy of the well-developed tuber and its relation 
to the stele of the main axis. Before dealing with this, the general plan 
of the stele must be mentioned. 
At the base of a fertile plant the entering root-strands unite to 
form a medullated protostele, which, interrupted by frequent small gaps, 
Fig. 2. 
passes into the peduncle of the cone, and by repeated division supplies 
the sporophylls. The vascular supply of the new tuber is given off but 
a short distance above the level of the roots. The leaf-traces, which 
consist of a single mesarch strand of xylem, are often given off so near 
the base of the plant that they are in direct connexion with the root- 
strands. 
The structure of the present specimen will be clearer if sections are 
described, proceeding upwards from the base of the plant. In Fig. 3, 
sects. 9, 8, and 7 (drawn with the Abbe camera), the entering root- 
strands are seen to unite to form the main stele, which consists, at this 
level, of anastomosing meristeles arranged round a central mass of paren- 
chyma. In sect. 6, in position corresponding to the large central stele 
of previous sections, two steles are cut across, one consisting of a number 
of meristeles arranged roughly along two sides of a square, the other, 
a compact, medullated mass of xylem, with a well-marked gap, g, on 
the inner side. Both steles are associated with the exit of leaf-traces ; in 
