MORPHOLOGY OF PHYLLOGLOSSUM DRUMMONDII. 
675 
composite bundle passes down that stalk, the structure of which is shown in fig. 39. 
At the base of the stalk, about the level of the insertion of the foliage leaves, this 
composite bundle separates into strands of varying number, according to the number 
of the other organs of the plant; two examples from such plants are shown in 
figs. 43 a, b. In these it may be observed that the general plan is in both cases 
the same, though there is a difference in the number of the roots; also in (a) the 
strand which passes to the tuber (t), is derived directly and solely from the axis, 
while in b the bundle of the tuber (t) is derived partly from the axis and partly 
from the leaf (/,), which is situated above the insertion of the tuber, and appears to be 
the supernumerary and latest formed leaf, described above as being of inconstant 
occurrence. These few examples will suffice to show that there may be considerable 
variety in the arrangement of the vascular system of Phylloglossum, and that the 
irregularities are closely connected with the variations of arrangement of the organs. 
Concluding Remarks. 
The above description applies only to the vegetative organs of Phylloglossum Drum- 
mondii. The description of the structure of the sporangia, their development, and 
the possible results of their germination must be deferred for the present. In the 
light of Treub’s recent researches on the Lycopodiacece, the development of the 
vegetative organs of Phylloglossum acquires additional interest, and a comparison 
immediately suggests itself between the early stages of development of the sporo- 
phore of Lycopodium, and the germination of the tuber of Phylloglossum. It can 
hardly have escaped the notice of those acquainted with Treub’s memoir, that in 
certain points the correspondence is very marked, and it may be well to point out 
those characters where the similarity is most striking. As regards the general con¬ 
formation of the plant of Phylloglossum while young, a comparison may well be drawn 
with the young plant of Lycopodium cernuum shown in fig. 1, Plate XYI. of Treub’s 
memoir. At the base is a parenchymatous tuber (“tubercle embryonnaire ” of 
Treub), which corresponds in position and structure, though not in size, to the tuber 
of Phylloglossum; in both cases it is composed uniformly of parenchymatous cells, 
and in both plants the superficial cells may develop as root hairs. In that same 
figure three leaves are represented similar in their form and position to those of the 
simpler plants of Phylloglossum. As yet no root is visible in the young plant of 
Lycopodium, and, similarly in Phylloglossum, the formation of the first root is subse¬ 
quent to the appearance of the leaves. The foot, which is not shown in the figure of 
Lycopodium, is absent in Phylloglossum, but it is to be remembered that in this plant 
the place of the foot is taken physiologically, if not morphologically, by the stalk of 
the young tuber. Thus the correspondence of parts, as regards their external form, 
between the young dlant of Lycopodium cernuum and Phylloglossum is very close. 
The chief difference is in the relative size of the tuber ; in Phylloglossum the develop¬ 
ment of the tuber, and storing of nutritive materials in it, precede the development 
