62 THE PLANT WORLD. 



cells of the main stem are much larger than those of the branches. 

 The chlorophyll is arranged in a broad band around the central part 

 of the cell. Zoogonidia are formed in cells of the branches. Their 

 behavior is similar to those of Protococcus. 



PHAEOPHYCEiE, or Brown Algae.— Plants unicellular or 

 multicellular; plant body of varied form, sometimes of gigantic size; 

 often attached to rocks; chlorophyll hidden by brown color bodies; 

 reproduction by spores, by union of gametes, or by fecundation of Q,g^ 

 by spermatozoid. 



Brown Algae in almost every instance are marine plants, so that 

 they are not within the reach of most high school classes. 



Nereocystis. (Greek nereis, a mythological name, and kystis, a bladder). 



A member of this genus forms the common Bladder-kelp of Puget 

 sound waters and the northern part of the Pacific ocean. In the 

 region of Vancouver Island these plants grow to be about one hun- 

 dred feet in length. They are reported to be very much larger in the 

 more northern waters. A much-branched, root -like holdfast attaches 

 the plant firmly to the rocky sea-bottom. From this up to the sur- 

 face of the water extends a long slender stipe from half an inch to an 

 inch in diameter. Here the stipe becomes enlarged into a hollow bulb 

 or bladder, which being filled with air, floats on the surface. At the 

 top of the bulb are attached two groups of leaf -like laminae, which 

 float on or near the surface of the water like ribbons. If the entire 

 plant is one hundred feet long the stipe will probably be about fifty 

 feet long and the laminae about fifty. Late in the summer light brown 

 patches will often be found on some of these laminas. These are 

 made up of great numbers of little sac -like sporangia which contain 

 the spores. 



Young specimens of this plant (preserved in formalin) a foot or 

 two in length, but showing the structure and appearance of the 

 mature form perfectly, are at hand for distribution. A study of the 

 gross anatomy should suffice for this plant. 



Fucus. {Greek phykos, sea-weed). 



The rock-weed is the commonest Brown Alga met with on the 

 seashore. As its name indicates, it grows attached to rocks, between 

 tides, and when left exposed at low water may be seen hanging, drip- 

 ping and limp, from the sides of rocks. Like Spirogyra, it is de- 

 scribed in text-books so generally that nothing more need be said here. 



RHODOPHYCEiE, or Red Algse.— Plants multicellular; plant 

 body of very diverse forms, usually differentiated into root and stem; 

 chlorophyll hidden by a red coloring matter; reproduction much more 



