REPRODUCTION BY SPORES 29 



life and to reproduce again. It is destroyed just about as 

 effectively as in fission, in which all the mother substance 

 goes to the daughters. . 



The advance that is found in this method over simple 

 fission is not in preserving the parent cell and reducing 

 the degree of sacrifice, as was true of budding; but rather 

 it enables one cell in its destruction to produce many 

 young instead of two. This means a much more rapid 

 increase of the species, if only the spores are well enough 

 endowed to carry on the work. 



In addition to the advance mentioned above, it often 

 happens that there are other cells of the parent plant left 

 that did not take direct part in making the spores. Such 

 parts may later give rise to more spore-producmg cells, 

 and thus the organism may reproduce many times. 



4 Many Kinds of Spores. Time would fail us if we 

 should undertake to describe all the different kinds of 

 spores we find among plants. We say "among plants 

 because -animals rarely reproduce by spores. There are 

 a very few lowly animals that produce spores, and they are 

 so lowly that we scarcely know whether to call them 

 plants or animals. On the other hand, practically all 

 plants form spores. 



While most spores are formed as described above, 

 inside the old mother cell wall, this is by no means always 

 true In some cases spores may be merely cells formed 

 by pinching off pieces, so to speak, at the ends of thread- 

 like branches. In these cases they might be thought of 

 as a kind of bud. This is the case in the spores of toad- 

 stools and their close relatives. 



The spores of plants are varied in such a way that 

 they meet the needs of the plants in remarkable fashion. 

 They may be formed deep inside certain organs and so 

 need special devices to let them out, such as the active 

 bursting of a capsule; or they may be formed in the air 

 at the very tips of delicate branches, so that the least 



