CHAPTER VII 



PHYLUM I. MYXOPHYCEAE 



THE SLIME ALGAE 



213. The Slime Algae are the lowest and simplest 

 plants, and are often so minute as to require the highest 

 powers of the microscope for their study. Some of them 

 are single cells, while others are rows or masses of similar 

 or slightly different cells. In most Slime Algae the cells 

 are poorly developed, the walls being soft and easily 

 gelatinized and usually containing chitin, the nuclear 

 matter diffused and not bounded by a nuclear membrane, 

 and the cytoplasm containing no plastids. 



214. The dominant coloring matter of the cells, phy- 

 cocyanin, which is blue, is mostly distributed through- 

 out the protoplasm, and mixed with the chlorophyll and 

 more or less carotin give the blue-green, brown-green, 

 or smoky color found in this group. In the hystero- 

 phytes these are wanting. 



215. They reproduce asexually by fission, 

 and the formation of spores, and in the fila- 

 mentous forms by the breaking of the filaments 

 into short segments (hormogones) each of fig. 59.- 

 which then grows into a long filament. No theMyxo- 

 sexual reproduction is known. ^ ^'""^^' 



216. The Slime Algae mostly live in the water, getting 

 their nourishment from the solutions it contains. The 

 green plants (holophytes) are able to use carbon dioxide, 

 but those not green (hysterophytes) are typically par- 

 asitic or saprophytic. 



163 



