Lycopodium complanatum and Lycopodhim clavatum. 233 
3. The roots arise endogenously near the apex of the stem, except the 
first root, which, according to Bruchmann, arises endogenously from the base 
of the ‘ hypocotyl.’ The growth of the roots formed at the apex remains 
arrested for a time, and then they either grow out at right angles to the 
stem or they may take a downward course through the cortex of the stem. 
4. The branching of the roots appears to be a form of dichotomy, but 
one branchlet is generally less vigorous than the other, and receives a 
smaller strand of vascular tissue. 
5. In L. complanatum a short strand from the main stele passes into 
the foot, and the appearance of the peripheral cells of the latter is such that 
the possibility that it may still act as an absorptive organ after the dis- 
appearance of the prothallus is not excluded. 
6. The arrangement of the vascular tissues at the base of the stem 
shows much irregularity. The xylem strands appear to be continuous with 
those of the first root, and an arrangement very similar to that occurring 
at the base of the root may be seen immediately above the point where the 
root comes off. At this point a fusion of two or of all three xylem strands 
takes place. 
7. The xylem strands take a very irregular course, fusing with one 
another and subdividing in the lower part of the stem, probably due to 
the frequent bending in this region. 
8. The upper part of the stem shows a tri- or tetrarch arrangement of 
xylem with central metaxylem, generally connected with two or more 
groups of protoxylem. 
9. The apex of the stem is occupied by several large actively dividing 
cells. 
10. Branching of the stem takes place by dichotomy, but the growth 
of one of the branches is generally stronger than that of the other ; the 
retardation of one of the branches may result in the formation of a pseudo- 
adventitious bud in the case of A. complanatum. 
it. The first leaves are scale-like, without vascular bundles, and 
arranged in an irregular spiral round the stem. The later leaves have a 
vascular strand, which consists of a few very narrow tracheides surrounded 
by a more or less thick-walled bast. 
In conclusion, I should like to add that this investigation was under- 
taken at the suggestion of Professor Weiss, to whom my best thanks are 
due for the valuable suggestions and advice which he has given me 
throughout. I also wish to express my thanks to Dr. Bruchmann for his 
readiness in agreeing to the publication of this investigation, made upon 
material generously supplied by him and intended primarily for museum 
purposes. 
