HIGHER BLUE GREENS 167 



their component cells other reproductive bodies (hormo- 

 gones) are formed. 



230. On account of their minuteness, bacteria may be 

 picked up by currents of air and borne long distances, 

 and in this way they are doubtless often carried from 

 place to place. When a pool of putrid water dries up, 

 the bacteria with which it swarmed are blown away with 

 the dust and dirt, dropping everywhere into pools, upon 

 plants and animals living and dead, and even entering 

 our lungs with the air we breathe. 



Class 2. HOLOPLASTIDEAE 

 The Higher Blue Greens 



231. This little class, of about 20 species, includes 

 SHme Algae, in which the nucleus is defined by a nuclear 

 membrane, and the coloring matter is concentrated in 

 one or more plastids. There is but one order, the 

 Glaucocystales, and a single family (Glaucocystaceae) of 

 unicellular plants. The type genus is Glaucocystis. 



Laboratory Studies of the Myxophyceae. With the fore- 

 going sciicrul statements of the structure and life of the Slime 

 Algae including the Bacteria, the student must now make some 

 examination of them by means of a good compound microscope 

 in the laboratory. In his examination he should make careful 

 drawings accompanied by brief, necessary descriptions. It is a 

 good rule in the study of plants never to make a needless draw- 

 ing, nor write an unnecessary description. A second rule of still 

 greater importance insists upon the absolute truthfulness (ac- 

 curacy) of both drawings and descriptions. 



The following studies are suggested as useful. 



(a) Scrape off a little of the greenish slimy matter from a 

 damp wall, mounting it in water; examine und.cr a liigli power. 

 Some small blue-green or smoky-green cells will be found 

 belonging to the Blue-green Slimes (Chroococcus, etc.); of 



