(28) 



Following the slime-moulds stand the cases devoted to the 

 algae or seaweeds (cases 2 to 16), which may be briefly 

 defined as thallophytes with chlorophyl, the green coloring 

 matter of plants. The plants of this series are much more 

 variable in form than those of the preceding, and are also 

 much more numerous. Some forms are microscopic, others 

 attain considerable size. The first case of the series is occu- 

 pied by representatives of the blue-green algae (case 2) and 

 the diatoms. The plants of these two groups are minute, so 

 much so that in most cases the individuals can be well seen 

 only with the aid of a microscope. As one finds them in 

 nature they commonly form slimy or oozy masses which are 

 not particularly attractive to the naked eye, but under a com- 

 pound microscope they are of very great interest. Follow- 

 ing the series just mentioned are the green seaweeds (case 3) , 

 the group which includes the plants that are sometimes called 

 the pond-scums, green slimes, green felts and stoneworts. 

 Some of these are microscopic; however, some of the green 

 seaweeds attain a considerable size and begin to look a little 

 more like what are popularly termed "plants." After the 

 green seaweeds come the brown ones (cases 4 to 8) , and here 

 the largest kinds are included. In their tissues is found a 

 brownish pigment which obscures their green coloring matter. 

 To this group belong the widely distributed " gulf-weed" or 

 "sargasso-weed" (Sargassum) and the gigantic "great 

 kelp " of the Pacific Ocean, which is said to attain seven 

 hundred feet in length. The seaweeds culminate in the red 

 algae, a group in which the plants show some shade of red, 

 pink or purple; these (cases 9 to 16) exhibit a marvelous 

 range of form and color. The last group of cases contain- 

 ing this series is given to the group of red algae which are 

 known as the corallines, on account of their outward resem- 

 blance to the corals. These plants are thoroughly permeated 

 with lime and are often as hard and stone-like as any coral, 

 and build up reefs in the tropical oceans much as the corals do. 



The next great type of plant life is the fungi (cases 17 to 

 36). These, like the plants of the preceding group, vary 



