100 



icimi, the mucus tubes of Anthuritim, etc.) , large numbers of 

 (106) cases of this Sort are v/ell Icnovml. Tyloses of the secre- 

 tory^- glands, like those of the ducts, arise on th6 one hand 

 after injury (as, for example, according to Tison, in aut- 

 umnal defoliation) , on the other hand as "phenomena of sen- 

 ility" without previous injury. But it would be impossible 

 to say What factorys incite their formation, and whether 

 they have any significance whatever for the life-activity of 

 the organism as a whole. 



3f Finally, those tyloses remain still to be consider- 

 ed, which grow into the air chambers of the stomata and fill 

 them partially or entirely]; Hypertrophies of this kind have 

 long been known in many plants; either the epidermal cells 

 lying adjacent to the guard cells , grow out on the inside 

 into large bags, as Haberlandt^ affirms for Tradescantia 

 viridis, (compare fig. 33) or the neighboring mesophyll 

 cells are distended and fill out the empty space, (fig. 34) 

 (The second type is more frequent, Schwendener observed the 

 same i n Prunug Laurocerasue and Camellia japonica. Molisch, 

 i^ ^radescantia guianensis. T. zebrina and t. pilosa . and 

 in Begonia gunnerifolia. Haberlandt in Pi3:ea elegans (fig. 34) 

 Mobius, in Ficus nerifolia, etc,^ The intercellular spaces 

 lying below the water clefts shov/ at times a very similar * 

 filling out. (TropaeolTjm Lobbianum, Cephalotus follicular is.) 

 Occasionally the walls of the tyloses are greatly thickened 

 on the side turned toward the guard cells, (Ficus, Pilea, 

 fig. 34.) 



It has not yet been observed whether tyloses are 

 produced in the inner cavities of stomata after injury, but 

 (107) it may be possible to prove this by future investigations. 



They are produced' chiefly on ageing organs, further, accord- 

 ing to Haberlandt, on such as suffer from l&ck of v;ater. A 



1. ITnger Anat, u. Phys. d. Pfl., Pest 1855, p. 213. Heg- 

 elmaier and Pfeffer im Tagebl. d. laturf ,-Sers. Leipaig, 187E 

 p. 144,, 145, Mavr, Ueb. d. Verteil. d. Harzes in uns. wich- 

 tigsten Hadelholzbaumen. Flora, 1883, Bd, LXVI, p,, 221, En*- 

 teh»'u, Verteil. d, Sekretionsorg, d, Fichte u, Larche, Bot, 

 Cbl», 1884, Bd. XX, p. 278. Trecul, s, 1. cellules qui ex- 

 istent a 1* inter, d, canaux du sue propre du Brucea ferrug- 

 inea. C, R. Acad. Sc. Paris, 1887, T. CIV, p. 1223. Tschirch, 

 Angew,' Pfl, -Anat,, 1889, Bd. I, fig. 565. Conwentz, loc. cit. 

 Mobius, Japanische Lackbuiii, Rhus vernicifera. Abh. Senckenb. 

 ITaturf. Ges, 1899, Bd. XX, p. 201. Costerus, Les petits point 

 fences d. feuilles des Connarus, Ann. J. Bot. Buitenzorg. 

 1899, Suppl, II, p. 109. 



a, Ueb, d, Bezieh, zw. Funktion u. Lage des Zellkerns 

 bei d. Pf 1. Jena 1887, 



3, Schwendener, Bau und Meckanik d. Sp^|;toffn, 1881. Ges. 

 Abh. 1898, Bd.I.p. 62. Haberlandt, Physio^, ^flanzenaieobomie 

 p, 400. Molisch loc. cit. Mobius, Beitr. a. Anat. d, Fious- 

 Blatter. Ber. Senckenberg, Haturf. Ges, :^887 , p. 117. 



„ 4. I>e Bary, Vergl, Anat. d, Veget,-0rg, , 1877, p. 55, 

 Gobel , Pflanzenbiol. Schild., 1891, 6d, II, p, 114. 



