[13] For example, silicon is used by some plants in strengthening supporting tissues. Buckwheat thrives better when supplied with a chloride.
[14] Evidence points to the belief that certain cells of the host form substances which attract, chemitropically, the fungus threads, and that in these cells the fungus threads are more abundant than in others. Furthermore in the vicinity of the nucleus of the host seems to be the place where these activities are more marked.
[15] In lieu of Arisæma make a practical study of the pea. See paragraph 216a.
[16] Dissolve a half gram of osmic acid in 50 cc. of water and keep tightly corked when not using.
[17] In Engler & Prantl’s Pflanzenfamilien, Wille uses the term class for these principal subdivisions of the algæ. Systematists are not yet agreed upon a uniform use of the terms.
[18] See Bot. Gaz., 17, 389, 1892.
[19] Class Myxomycetes, or Mycetozoa.—To this class belong the “slime molds,” low organisms consisting of masses of naked protoplasm which flows among decaying leaves and in decaying wood, coming to the surface to fruit. The fruit in many cases resembles miniature puff-balls, and these plants were formerly classed with the puff-balls. The spores germinate by forming swarm spores which unite to form a small plasmodium, which in turn grows to form a large plasmodium or protoplasmic mass. It is doubtful if they are any more plant than animal organisms. Examples: Trichia, Arcyria, Stemonitis, Physarum, Ceratiomyxa, etc., on rotten wood; Plasmodiophora brassicæ is a parasite causing club foot of cabbage, radishes, etc. It lives within the roots, causing large knots and swellings on the same.
[20] As suborder in Engler and Prantl.
[21] As suborder in Engler and Prantl.
[22] As suborder in Engler and Prantl.