109 



pXet^ly resemble Erineura hairs (Comptire also fig, 44), (The 

 fact that the forms of the T^rineura hairs sometimes occur dif- 

 ferently on different plant organS.^ is worth Aotice and de- 

 serves further investigation, (compare Prank, loo. clt, p»44). 



Only experiments will give a reliable ans^rer to the 

 l[uestion Vi^ether the epidermis of ai; | L plants can he stiraulated 

 to the production of hairs hy menns of certain poisons, Bis- 

 ooveries in nature make it seem rery. probable primarily that 

 the peculiarity of the epidermal cells nov under discussion is 

 at least very vvidely distributed, since Erineum gMls are to 

 be found upon representatives of the most varies plant fam- 

 ilies, The most numerous of the irtive Erineum galls are 

 found upon deoiduouff trees;- among herbaceous plants the 

 preference for the Rosaoeae is strikingly noticeable. 



(111) 



fore detailed sumnaries are to be found in the work of 

 yjuxg^x . Prank floe. cit. p. 47l, v. Schleohtendal , Uegtr 

 (loo, oit,), Darboux and Hduard^ and others, 



Finally brief mention must still be made of the hair-like 

 outgrowths which are formed on different kinds of plants under 

 the. influence of Cyanophyoeaa . In the case of ^^^^l^'.^^^l^^ 

 colonies always settle in the hollows at the base of the upper 

 leaf lobes. A few of the epidermoj cells covering the liollow, 

 grow out into long hairs. In the leaf ears of the Ij^jrwort 

 Blasia, colonized by Kostoc strings, may be f eun d similar unx- 

 cellular, much branched hairs. In the Anthocerotaceae also 

 the wall cells of the mUcus hollows inhabited by Wostoo grow^ 



^ LOG. cit. p. 372. (therein also references to the 

 older literature and some remarks on the plant geographicai 

 distribution of the Erineum galls, 



^ LOC. cit. Compare further: Uebersicht der bis. J. 2. 

 bekannten mitteleuropaischen'PhytoptOcecidien und ihrer Litt, 

 Zeitschr, f, Haturwis., 1888, Bd. LV, p. 480. 



^ Catalogue sustem. d. 2aoceeidies le l^BurOpe et du 

 bassin mediterraneen, Paris, 190yL, 



