95 



As regards their contents , many tyloses correspond 

 to w6od«-parencliyma cells, in v/Maiti they store up abundant 

 starch, "Molisch found tyloses containing starch in Aris- ' 

 tolochia, Asarum, Hobina, Maclura, Vitis, Ampelopsis, Morus, 

 Cuspidaria, Laurus, Oohroma, Sparmannia, Ficus and Ulftus, 

 so abundantly in the rhizomes of the Aristolochiaceae, that 

 the ducts seemed In places to be 'plugged up with" starch,'' 

 Crystals, as contents of tyloses, are of little importance. 

 fbo tyloses of Si deroxy l on olnereum often contain one crystal, 

 more rarely those of Maclura .tinctoria, Piratinera g u ianemsl s 

 LoscoptergiTO Lorentzii, and Yltis^ Molisch found iyTosms 

 of Ulmus filled wi'ch calcram carbonate. In regard to wound 

 gums contained in the tyloses, refer to the statements of 

 ¥ill.2 



(102) Amon^ the most important characteristics of tyloses 

 is the fact that they ate uniigellulart Despite the extent 

 which they often attain, cell-diyision is omitted in almost 

 all cases, Molisch" has disproved the statements of de Bary,* 

 (loc, cit,) .Trecu3,, Gris°, and others, who thought they had 

 observed a separation of the tyloses from the mother cell, 

 Molisch could prove multicellular tyloses only in the ex- 

 ceptional .cases of Cuspldaria pterocarpa a nd Eobina, iThor^ 

 ough proff is needed of the statements of Stoll^ that the 

 wood In Passiflora quadrangularis taJses part in callus f oni>- 

 ation by'means of tyloses. He says that these after repeated 

 division, fill out the lumen of the duct near a wounded sur- 

 face -v7ith a tissue that finally presses out over the cut sur- 

 face, 



The distribution Of tyloses in ducts is almost uni- 

 versal in vascular plants, They are foimd in the parts of 



It Compare here also Rees's Pur'Kritik d, Bohm ^ schen 

 Ansioht ub, d4"Entwickelungsgesch, und Funktion der Thyllen 

 Bot, Ztg, 1868, Bd, XX^I, p. 1, 



S, Molisch, loc. cit. p. 275 and Vergl, Anat. d, Holzes 

 der Ebenaceen u, ihrer Terwahdten, Sitzungsber. Akad. Wiss. 

 lien, 1879, Bd. LXZX, Abt. I, p, 65. 



3, Ueb, d, Sekretibddung im TAind- u, Kernholz, Arch. f. 

 Pharmacie, 1899, Bd, OCXXXVII, p, 369. 



4, Vergl, Anat, dl Yegetationsorg, p. 178. « 



5, Trecul, Rech; s. I'origine d. bourgeons adventifs. Ann, 

 So. Uat. Bot. 1847,^3®^ ser,, T, VIII, p, 273. Gris, SUr la 

 moelle des pi. ligneuses. Ibid., 1872, 5°^® ser. T. XIV, p. 34. 



6, 'Ueb. d. Bildung des Callus, Botan. Zeitg. , 1874, Bd-, 

 XXXII, p, 737. 



