Lycopodium complanatum and Lycopodium clavatum. 225 
In the older sporophyte of L. complanatum a complication was brought 
about in the stelar arrangement, due to the fact that dichotomy had taken 
place very early ; one of the branches had been arrested in its growth, 
forming what Bruchmann 1 describes as a pseudo-adventitious bud, while 
the other was continued as the main stem and had again dichotomized 
several times. In the pseudo-adventitious bud, although this was only 
visible as a slight swelling near the foot, a root had already begun to grow 
out (Fig. 15). The apical growth of the branch had been much delayed, 
yet a stimulus to rapid growth had evidently been given, for the apex had 
just dichotomized, and the root was pushing through the outer layers of 
the cortex. 
The changes in the arrangement of the xylem and phloem in the main 
stem of this second sporophyte were very rapid. In Diagram 1, Figs. 11 
and 12, and Diagram 4, Figs. 1-23, some of the changes which occur in the 
first 2 mm. of the stem region above the point where the first root comes 
off are shown. It will be seen that sometimes the xylem groups all unite, 
forming variously shaped masses (see Diagram 4, Figs. 10, 11, 16, 20, 21) ; 
sometimes islands of phloem are formed by the closing round of the xylem 
(see Diagram 4, Figs. 10, 16, 19, and 20), or the phloem may remain 
external to the xylem surrounding it, and forming numerous bays or 
cutting off smaller or larger portions, of various shapes (see Diagram 4, 
Figs. 18, 19, 22, 23). There is, however, a tendency to the formation of 
a central mass of metaxylem. Diagram 4, Fig. 23, shows a section in which 
a central mass of metaxylem is separated off from three groups of smaller 
elements. As a rule, however, the central mass remains connected with at 
least one of the protoxylem groups. 
In the sporophytes of L. clavatum there was less complication in the 
course of the xylem strand throughout the stem. A short distance above 
the point where the first root came off there were three separate groups of 
xylem, with phloem in the centre and extending between the groups ; then 
one or two of the groups of xylem united at the periphery, apparently by 
extension of the protoxylem elements, and immediately after four groups 
separated out. Higher up two of the groups united again, by extension of 
protoxylem elements, and at the same time by centripetal development 
of metaxylem either all three groups united in the centre or one remained 
separate. The older sporophyte showed variations from the arrangement 
described above, in some parts of the upper portion of the stem, the 
protoxylem elements extending towards the centre in such a manner 
that a very irregular arrangement occurred, but on the whole the tendency 
was for the arrangement to become more uniform, producing a radial 
arrangement with the number of rays increased in the stouter portions of 
the stem and where dichotomy was about to take place. 
1 Bruchmann, loc. cit., p. 70. 
