GENERAL MORPHOLOGY 
297 
the sporophylls no longer serve as assimilating leaves, but appear as chaffy 
scales, performing a protective function. 
the comparative study of the mature 
sporophyte in the genus Lycopodium 
any other evolutionary story than this. 
The only other living genus of 
eligulate Lycopods is the monotypic 
Phylloglossum, long recognised as the 
simplest of them all. The mature plant 
as seen above ground consists of a tuft 
of almost cylindrical assimilating leaves, 
from the midst of which rises the 
simple axis terminated by the short 
strobilus ; below ground are found two 
ovate storage tubers, one dating from 
the preceding year and in course of 
exhaustion, the other in course of 
development as a store for the succeed- 
There are also one or more 
roots (Fig. 145). The lower parts of 
this curious little plant cannot be 
properly understood till it is compared 
with the embryos of certain species of 
Lycopodium, for it repeats in its annual 
growths their embryonic characters: the 
discussion of them will therefore be 
postponed (p. 351). 
ing year. 
It would be difficult to read from 
FIG. 145. 
Phylloglossum Drummondit, Kunze. A= 
apex of a germinated tuber ; 4, dy, dg, leaves; sp 
=the young strobilus. X15. B8=the whole 
plant. x one-half. 7¢j;=the old tuber; “= 
the young tuber; »=root. C=sporophyll with 
sporangium seen from above. x12. (After 
Engler and Prantl.) 
The very short strobilus shows a similarity to the 
Urostachya rather than to the Ahopalostachya section of the genus: this is 
B 
Fic. 146. 
Phylloglossum Drummondit, 
Kunze. 4 =a plant showing pro- 
tophylls and strobilus : one sporo- 
phyll of the latter is at a distance 
below the rest, intercalary growth 
having taken place in the axis 
above it. x3. B=a plant with 
the strobilus branched into two 
unequal parts. x 3. 
seen in the smooth margin of the rather fleshy 
sporophylls, as well as in the incomplete protection 
of the sporangia. It is interesting to note that tran- 
sitions are occasionally found between the foliage 
leaves (protophylls) and the sporophylls: Fig. 
146 4 shows a case where a single sporophyll of 
larger size than the normal, with a sporangium 
in its axil, stands isolated some way below the 
strobilus: thus it is intermediate both in position 
and in character between the two types. A small 
protophyll without any sporangium may also 
sometimes be found at the base of the pedicel. 
Dichotomous branching of the strobilus is some- 
times seen, but it is rare: an example is shown 
in Fig. 1468. Such features are important for 
comparison with Lycopodium, and indicate that 
there is a close relation between the two genera. 
