74 



FOOTNOTES FROM 



supposed to be analogous to the spermatozoids produced 

 in the antheridia of the algae and mosses, and which 

 seem to perform an essential part in the reproduction of 

 almost all cryptogarnic plants. All these kinds of fruc- 

 tification are sometimes found on one plant at the same 

 time, and each of them is capable, under certain condi- 

 tions, of producing perfect individuals similar to the 

 parent plant. It must not be supposed, however, that 

 they all exercise their functions at one and the same 



FIG. 8. UMBILICARIA POLYMORPHA. 



Section of a Sper- 

 magone. 



Section of apotheeium and of thal- 

 lus, showing the rhizinse. 



Section of thallus, show- 

 ing spermagone. 



time for nature is never prodigally wasteful of her 

 resources ; but where situation, temperature, or other 

 conditions interrupt propagation by one mode, another is 

 developed more exuberantly than usual to supply its 

 place. If there be not conditions to produce perfect 

 apothecia, there will be soridia, pulvinuli, or cyphellse 

 instead ; and just as the chances of failure are great, so 

 are the modes of reproduction increased : and what an 



