>it' 



tumescences by destroying the organs on the leaves of Conoce- 

 (88) phalustovalus and C. suaveolen s v/hich e laminate water, The re- 

 sulting s-arplus of water caused the- formation of intijme sconces. 

 His, method consisted of painting the leaves of the plants under 

 experiment w'ith a one per cent alcbhMic sublimate solution. 

 A few days after the poisoning of the hydratea, thick bunches 

 of colorless hairs (compare fit;, 23) were found where groups of 

 transient glandular hairs had stood on the young, immature leavi 

 In their production those parenchyton, cells especially partici*- 

 pated which enclose the vascular bundles, 



"Dn a circular spot these cells are drawn out in anti- 

 > clinic curves and grow into long sacs, which remain unbrokenly 

 connected with one another at the base showing rather n-umerous 

 periclinic and, in part, anticlinic divisions. First a flat 

 conical or disc-shaped tissue body is produoed, which brea.ks 

 thru the overlying leaf tissue (palisade and v;at6r-tissues , 

 epidermis) . Then the upper parts of the sacs grow out into long, 

 colorless hairs, resembling root-hairs which stand out from one 

 another like bristles of a brush, lot -infrequently distended 

 like clubs at the free end, they possess a living cytoplasmic 

 wall-covering with a roundish nucleus. On the edge of the disc- 

 like tissue body several rows of palisade cells are abundantly 

 elongated. Their chromataphores usually degenerate before this, 

 or at most remain in the lower po.rt of the sacs, (loc. cit, 

 p. 109, 110)", Besides the palisade cells, those of the xylem 

 and of the wood-parenchyma in the vasciilar bundles can partici- 

 pate in this growth. After about a week, the delicate new form- 

 ations disintegrate and are replaced by excrescences on the 

 underside of the leaf, from the epidermis and vmtfer- tissue layer 

 of which unicellular or multicellular v^rater blisters are pro- 

 duced. Haberlandt compares these with the hosiologous organs of 

 Mesembrianthemum orystallinurn . In my opinion, intumescences are 

 concerned here as v;ell as in the bu^iches of hairs differently 

 (89) developed. 



These are differentiated from those earlier described 

 by their ability to give off water. Haberlandt tries to 

 give them an especial significance, since he- considers 

 their formation an expedient reaction of the plant, which 

 after a loss of the normal hydathodes , "can develop entire 

 ly new organs for eliminating water, essentially differ- 

 ent histologically, and of other develo-pmental origin, 

 than any occuring in the normal developmental process of 

 the plant." I have already stated mj view-^that there is no 

 necessity for speaking of these described excrescences as 

 the "new organs", and 1 have compared the compensatory 

 hydathodes described by Haberlandt with callus formations 

 since the latter at times have a similar structure and can 

 also Qccasionaly eliminate water. ^ More apropos is a com- 

 parison with the above described intumescences with which 

 they also correspond etiologically. Haberlandt himself 

 has already called attention to the similarity hetween the 

 structures whiich ho developed artificially, and the hyper- 

 trophies observed by Sorauer and others. The question as 

 to v/hether the latter, like the compensatory organs of COno 



1. Beitr. a, Anat. d. Gallon, Flora. 1^00, Bd. LXXXYII,p« 117. 



S. Compare here also Ivlollisch, Ueber lokalen Blutungsdruck 

 u. s. Uraschen. Bot. Zeitg. , 1902, Ed, LX, p. 45. 



