ANATOMY OF TISSUES. 81 
cludes thal with and without the rudimentary leaf, the latter 
in that of the Jungermanniaceae including all three forms. 
One more peculiarity of this group must be mentioned 
before taking up the description of the thalloid hepaties sepa- 
rately. The difference in the mode of the development of the 
spore, on and after germination, has already been referred to as 
an intimation of the rank of the mature plant. That is, a spore 
destined to produce an ordinary fungous growth, germinates 
by sending out cylindrical tubes, which grow and_ branch 
repeatedly ; walls are formed at right angles with the long 
diameter of these branches, the latter adhere and grow together, 
and in this manner the so-called false tissue is formed. On the 
other hand, on the germination of a spore of higher plants, a 
wall is formed separating the spore into two cells ; each of these 
again divides, until a body of cells results and by a special 
manner of growth and formation of new cells the various 
tissues are produced. In certain algae there is a combination 
of both these methods of growth, as is illustrated in Fucus. In 
the Bryophytes, which includes both Hepaticae and Musci, 
there is still a vestige of that manner of development which 
culminates in the production of the false tissue of the fungi. 
The asexually produced spore of the Bryophytes germinates 
either by growing into a small plate-like structure, or by 
extending itself into a filamentous branched body. Both of 
these are called protonema, and the latter resembles the myce- 
lium of the fungi, except that a part or the whole of it is sup- 
plied with chlorophyll. 
4. Thalloid Hepaticae. 
The real plant arises from this plate-like structure or pro- 
tonema just described. One or more of its cells becomes meri- 
stematic and develops into an apical cell or row. The shape 
and manner of division of this cell or cells varies in the different 
