Cf96) 



177 



Certain Isacteria are known to incite the roots of 



ScleI^TnS?????r,^''nl^^ production of extensive tub- 

 ercles, consisting of par|nchymatic, undifferentiated 



J !v®* Jf ^^^^^ ^°* ^*°P *° consider the question 

 . • whether this is to be included among the new patholo- 

 gical formations, or not. We will speak later of the 

 swellings caused by bacteria on Pinus halepensis and 



Plea europaea . ■ ■ "^ 



07~the Bumycetes . all the chief groups come under con- 

 sideration here; numerous Phycomycetes, Uredineae, Us- 

 tilagineae, Asc-omycetes and Basidiojjjycetes develop kat- 

 aplastic plant galls. The galls of the Synchytriae 

 (Phycom^rcetes) were mentioned above (p. 108) . Among the 

 Uredineae, I refer, for example to the Aecidia galls 

 of Viola, Berberis, Rhannus, Urtica, to the branches of 

 Vacciniuro Vitis Idaea attackek by Oalyptospora go-pper- 

 tiana . to -tnose of Juni-perus infected by Qymno sporangium, 

 to the products of Peridermiura Pini . which resemble wmanci- 

 wood, etc, and to the bizarre branching, produced by " 

 Caeoma deformans on Thujopsis, Of the galls of the Us- 

 tilagineae, I will name only the smut boils on maize in- 

 florescsncee, (istilago Maydi s) the gills of Ustilago 

 Treubii^,' those ot various Ur"o cyst is species above and 

 belov/ ground. Of the Ascomyoetes, especially the prim?- 

 itive forns (protomyces, Exoascus) come under consider- 

 ation as producers of galls, Besides these, still a few 

 representatives of the Carpoasci vrhich produce canker- 

 like woody excrescenees (canker of the larch produced 

 by Dasyscypha Willkomii etc) ©f the Basidiomycetes, 

 various Exob as idium. species are of interest to us as 

 producers of galls. ^ 



Tissue exoresoences caused by Algae are known es-' 

 pecially for Cystoseira opuntioides and 0. ericoides, 

 upon tvhich aoc o r ding t o Val i ant e* and Sauvageuo Streb- 

 lonemopsis irritans and Eo to carpus Valiant ei live par- 



Of the higher plants the Loranthaceae are almost the 

 only ones coming under consideration here* They often 

 produce enormous gall formations, the so-called wood 

 roses, on their host plants. The infected branch of the 



1. Compare Prank, Lehrbuch der Botanik, 1892, Bd. I, p. 268 

 ff; Therein also many further literature references. For var- 

 iously formed "tubercles" compare the dissertations by 0. Schwan, 

 Ueber d, Vorkommen v, Y/urzelbakterien in abnorm verdickten Wur-- 

 aeln v. Phaseolus mu'itiflorus r Erlan^en, 1398. - On the tubercle 

 outgroT/ths inhabited by bacteria, found on many marine algae, 

 compare above p» 1.54, note E. 



2. SolmS-Laubach. Ustilago Treubii. Ann, Jard. Bot. de Bui- 

 tenaorg, 1887, T, ViD, p. 79. We will sp'eak again of this gall 

 in the section on prosoplasmas, 



3. Compare especially the text book by v. Tubeuf , Pflanzen- 

 krankh. , durck kryptogame Parasiten verursacht, 1895, Further 

 literature will be named later. 



4. VaXiante, Sopra un Ectocarpea parasita della Cystosetis 

 opunti oides « StreblonemoDSis irritans . little, Zool, Stat, 

 lTeapel,~I§'§3, Bf^, VI, p. 489. Compare t,he illustrations in En&- 

 ler-Prantl, Naturl, pflanzenfam. Bd, I, 2, p, 189. 



5. Sauvageau, Sur quelqu, algues phfeospo?$es parasites, J» de 

 Bot., 1892, T. VI, p. 57 p * ' 



