Fungi. 209 



the various fungi may react to modify them, but they are no more ex- 

 empt from such influences than the higher organisms, and it may safely 

 be assumed that the differences between them are, in many cases, due to 

 their different food and habit of life. 



There is much reason for believing that many of the fungi are simply 

 degenerated algae. The algae are cellular ; some of them consist of only 

 a root-like body, some of only a branching naked stem, some of just an 

 expanded leaf, while some of the most complex may have all these 

 parts. Those algae that have something like a root do not get any nour- 

 ishment through it. It serves to hold on by, but is not a genuine root, 

 and many have no root of any sort. The f ucoid seaweeds are some- 

 times 30 or 40 feet long, and the algae grade all the way down from that 

 to a microscopical size. These minute algae belong to several orders, as 

 the Desmids, Diatoms and Palmellaceae. They consist of a single spheri- 

 cal cell each. At maturity this cell is divided by a partition across the 

 middle ; each half becomes developed into a single-celled plant like the 

 first, in the case of the Diatoms and Desmids generally, but it may be 

 divided into four parts, as in the case of some of the Palmellaceae. 



Protococcus is the name of a genus of the last order. Its coloring 

 matter is often red mixed with the green of its chlorophyl. It is found 

 everywhere, from the snows of Greenland to the hot water of the Red 

 Sea, and flourishes equally well in either. Growing with surprising 

 rapidity, it scatters its cells so thickly through the snow or water as to 

 give its color to either. The cells may become dry and will not lose their 

 germinating power in several years. They are carried everywhere by the 

 winds, and may be found in the mud of roof gutters and in rain water 

 cisterns. According to Huxley, the cell wall is tough, transparent and 

 structureless, composed chiefly of cellulose colored green, or red and 

 green. Inside the, cell is viscid and granular protoplasm. Its size 

 ranges from j^^ to ^ of an inch in diameter. It cannot grow in the 

 dark, as does the fungus Torula. In daylight it decomposes carbonic 

 acid gas, appropriating the carbon and setting the oxygen free. This 

 power of getting carbon from carbonic dioxide is what chiefly dis- 

 tinguishes this and all plants containing chlorophyl from Torulae and 

 the other fungi. In the dark, Protococcus, like all other living things, 

 undergoes oxidation and gives off carbonic anhydride (C 2 ). 



Sometimes the cell wall vanishes and the naked protoplasm swims 

 about and may undergo division and multiplication in this state. There 

 are many species of these small organisms that produce spores for 

 propagation in addition to their other method of reproduction by fission. 

 The spores are produced thus : Two individuals approach each other and 

 develop a little tubercle at one end of each. These come into contact, 

 the walls between them disappear, and they are cemented into one, form- 



