236 PLANT LIFE 
formed at meiosis often separate as four 
spores, each of which may give rise to a new 
plant destined in time to produce gametes. 
Thus meiosis in plants has come to be asso- 
ciated with a special kind of reproductive 
multiplication which is sometimes called 
asexual reproduction. 
It would be better to replace the terms 
sexual and asexual reproduction by the terms 
gametic and meiotic reproduction, and thus 
do away with a misleading antithesis. For 
** asexual’? and “sexual” reproduction are 
parts of one process, carried through in two 
stages. The two phases of reproduction, 
gametic and meiotic, in all the higher plants are 
associated with two distinct stages in the life 
history. One of these begins with the fertilisa- 
tion of the egg, and ends in the meiotic 
divisions. The spores, which are formed as 
the result of meiosis, inaugurate the second 
stage of the life history in which the differ- 
entiation of sexual cells takes place. 
This rhythmic alternation of a spore-pro- 
ducing with a gamete-producing generation 
is well illustrated by the fern. Starting with 
the fertilised egg, an embryo is produced, 
which grows into the ordinary fern. If the 
backs of the leaves are inspected, brown spots 
or stripes may often be seen, and these are 
found to consist of small capsules or spor- 
angia. A young sporangium contains a fairly 
definite mass of internal cells which are 
enclosed by nutritive tissues, the whole being 
