108 BIOLOGY. [Book n. 



elongated form of a filament, simple in certain intermediary algae 

 (phycomyceta), divided transversely by partitions in others, and 

 sometimes ramified (mucedinese). 



The nutritive characteristic of the mushrooms is the absence 

 of chlorophyll. Thi-ough this characteristic the mushrooms 

 resemble the animal organisms. They are incapable of 

 assimilating direct the aerian carbon, and have no need of light. 

 We can even see some of them living under the soil, as for instance 

 the truffles, and so on. From the absence of chlorophyll it also 

 results that the mushrooms, like animals, have need of aliments 

 wholly prepared, of combinations carbonised, assimilated by other 

 organs. Thus when they are not parasites they have to live at 

 the expense of organic m^atters in process of decomposition. 



Furthermore, and this is a general characteristic, they are 

 incapable of forming a single granule of starch. This fact 

 explains in a certain measure the office of chlorophyll in the 

 synthetic chemistry of the vegetal organism, and serves us as 

 transition to pass to the following chapter. 



