1 70 TEXT-BOOK OF FUNGI 



glaucum bored through the cell-walls of elder pith, and 

 passed through the pits of coniferous wood that had been 

 injected with a positively chemotactic solution. 



Chemotropism is supposed to be the directive force 

 accounting for many phenomena presented by fungi. Lind 

 considers that the penetration of fungi into chalk, egg- 

 shell, or bone is due to a chemotactic stimulus furnished 

 by an organic or inorganic food-material. Groom states 

 that the hyphae of a mycorrhiza present in Thismia, on 

 entering a cell, go directly to the nucleus owing to this 

 same influence. I have shown that a specific substance 

 or substances present in the cells of a plant is the prime 

 factor in attracting the germ-tubes of parasitic fungi into 

 the tissues of the host-plant. Only the germ-tubes of the 

 fungus that responds to such attraction can enter the plant ; 

 consequently, when a spore germinates on other than the 

 host having the chemotactic substance to which the germ- 

 tube responds, no infection takes place. This accounts 

 for the same kind of fungus being always parasitic on the 

 same kind of host-plant, or on allied species. 



Groom, Ann, Bot., 9, p. 327. 



Lind, Pringsh. Jahrb., 32, p. 603 (1898). 



Massee, Phil. Trans. Roy. Soc., ser. B., 197, p. 7 (1904). 



Miyoshi, Bot. Ztg., 1894, p. i. 



Pringsh.Jahrb., 28, p. 269(1895). 

 Pfeffer, Ber. d. deutsch. Bot. Ges., i, p. 524 (1883). 



CHEMAUXISM 



This term is used by Renard to express the acceleration 

 of growth due to the presence of salts of copper in definite 



