113 



process may be repeated many successive tiraes, (loc, cit., 

 p, 185) . The same changes in form may be obtaineA by trans- 

 ferring the root -hairs from moist air into water or into con- 

 centrated nutrient solutions. It is even possible by these 

 methods to produce branched root-hai*s, occasionally mentioned 

 in the literature on thiS' subjept, 



The illustrations here shmrn should be oonvincing as to 

 the similar it jr of the Erineura^ hr4rs to deformed root-hairs. 

 In figure 44, the hairs of an Erineum of Acer oampestre are 

 shown side by side ^vith club-like root -hairs, beginnings of 

 branching showing on their distenfled Weads. Further, in 

 (figure 45, three irregularly waved hrirs from a blossom gall 

 (122) of PhjT'teuraa are shown side by side r/ith root -hairs, which 

 Sohwarz obtained by the methods desotibed above and which 

 show very similar alternating constructions and distensions. 



As Schwarz has .shown, these abnormal root-hairs ct6 pro- 

 duced after changes in the csraotlo pressure of the oell, 

 through retention in solutions which withdrr.w -T.ter from then, 

 as well. as by transferring from air to water. It does not 

 seem possible that, besides the action of y/ithdrr.wing water 

 produced by the effective solutions, even specific poisonous 

 action, proceeding from th-ese solutions may influence the 

 formation of irregularly deformed root-hairs. For comparison 

 with those above described, root-hairs of Sinapis seedlings 

 are also shown in figure 46, which were grown under treatment 

 with 'VGT^ dilute sublimate soliition. As may be se$n the 

 formal diversity is very great, even in adjacent hairs. 



Hypertrophies occur further on rhlzoids and root-hairs 

 after infection by foreign organisms '^. The abnormal pro- 

 gress of apical growth is connected supposedly with some ef- , 

 feet on the tuj^ger in the cell. The same forms as in Krineum- 

 and root-hairs are found in a number of other ttxbe-like cells, 

 which are similarly enlarged by apical grov/th. In the fol- 

 lowing fungus hyphae the S iphoneae and pollen tubes may be 

 briefly disciissed* The deformations of the fungus hyphae 

 are best known. They are extraordinatly gbujidant ana in 

 fact are present in any fungus -culture. The hyphae here and 

 there form isolated boil-like spherical distensions or plsces 

 with alternating narrow and wide liamina, corresponding to the 



^ Examples in Magnus, Ueb, Ohytridium tumefaciens n, sp. 

 in d. ^7urzelh. v. Geranium flabelligerum u, acanthonotum u.s, 

 w. Sitzungsber. Ges. Katurforsch. Fr. Berlin 1872, p. STj, 

 Goebei; Morph. und biol, Studien. Ann. Jard, Buitenaorg, T, 

 VII, p. 77, Boebel, Archegoniatenstudien, Flora, 1892, Bd, 

 LXXVI, p. 106 (Beob, an Polypadiinn obliquatum u, Trichoman«s 

 rigidura). Marchaftd, S. unenostochine© parasite. Bull, soc, 

 Bot, France, 1879, Bd, XXVI, p. 336 (Observations on infected 

 moss-rhizoids, especially Riccia). U©meo, Die Mykorrhiza 

 einiger Lebermoose. Ber. d. ]). Bot. Ces. 1899, Bd. XVII, p. ^ii 

 (Observations on Oalypogeia). Borzi, Rhis^omyea, nuovo Fictoi- 

 cete, Messina 18 84 (swellings on the root-hairs of many mono- 

 cotyledons and dicotyledons after infeetion with Rh. hypogeeaj. 



