CHAPTER XI. 
FERNS AND MOSSES. 
Tue preceding chapters of this book have dealt with flowering 
plants (phanerogams or seed-plants) because these are, in some 
respects, best suited for elementary study; but the beginner 
must not forget that the flowerless plants (cryptogams) are 
after all by far the most numerous, and include not only a great 
many conspicuous forms but also a vast number of small and 
microscopic ones. The term “ flowerless” is not a particularly 
happy one, for although it is true that these plants do not bear 
conspicuous flowers in the popular sense of the word, yet they 
may possess structures to which the name flower, in the 
sense of “a shoot modified for spore-bearing” (p. 92), cannot 
be refused. It would be much more correct to speak of “seed- 
less” plants, for such forms never possess those reproductive 
structures known as seeds, in each of which is found a dormant 
embryo capable of growing into a new plant if kept at a proper 
temperature and supplied with air and moisture (p. 142). 
CRYPTOGAMS are subdivided into three large groups, which, 
beginning with the highest, are: (1) Ferns and Fern-like Plants 
(Pteridophytes); (2) Mosses and Liverworts (Bryophytes) ; and 
(3) Leafiess Plants (Thallophytes). It will be most convenient 
to first say a little about the last-named group, and then to 
describe a moss and a fern in some detail. 
THALLOPHYTES are characterized by the fact that they 
are not divided into root, stem, and leaf, but consist of an ex- 
pansion which is called a thallus. They are propagated in 
various ways, but especially by minute dust-like spores. The 
group is subdivided into two series, (a) Alge, and (6) Fungi. 
Alge contain chlorophyll, as may be clearly seen in the green 
seaweeds, and also in the green scum which is often observed 
floating on the surface of stagnant water in ponds and ditches, 
as well as in the slimy masses of thread-like forms which are 
found in similar situations. The powdery green crust so com- 
monly noticed on old wooden fences and on the bark of trees 
is made up of innumerable minute rounded alge closely crowded 
144 
