growing so strongly and the new fornr.tion pushes outwnrd, " 

 While in the cnmbinl gr.ll of a Komatode shown in figure 88, 

 the epidermis persistently surrounds the luxuriant tissue ex- 

 cresconoe, we find in other galls that the covering tissue holds 

 its own only at the beginning so that in the end tears are 

 formed. In VJhich the more deeply-lying gall-tissue is exposed. 

 The galls of Aulax Hioracij . lasioptera and others ere "en- 

 closed" by a raoderaie dibveiopraent of the gall-excrescence. In 

 the case of nspooially luxuriantly detfelopod specimens, however, 

 the normal covering tissue is ruptured here and thore and the 

 formr.tion of wound cork is eventuclly necessary. In mrny Oyni- 

 pidoB galls (in the autumnal galls of Kourotorus lontioularis 

 n, numlsroatls etc,) from the very beginning only small tissue 

 complex in the Interior of the organ, producing the .gall, Is 

 capable of Increasing, "gall-plastem")/ The outgrowth progresses 

 rapidly, breaks through the Inactive outer tissue layers and de- 

 velops its ovm covering tissue,-, just as the "free" walled galls 

 of Hormomyja piljgeras are formed (see above, figure 87), Figure 

 89 siiowp in cross-section the froR oamblal gall of Biorrhias 

 aptern (the winter generation of the nbove-naraed O yniPS t ermin- 

 ajLis ) V;hich abounds on the roots and ylsung branches ox Querous. 

 The endogenous origin IB made clear by the drawiijig, v/lthout 

 further explanation, 



(281) The nammer of production of "free** galls necessitates the 



fact that they iisually appear aH more or less independent appen- 

 dages of the plant or^;n* bearing the gall. However, It would be 

 absolutely unjustifiable to wish to draw conclusions from *i^J 

 external appearances of a mature gall as to the ontogeny of this 

 gall, which, like that of Biorrhiza aptera . rests like an inde- 

 pendent organ upon its substratum. Thus, for example, the gall 

 apple, produced by Spathegnster boocarum (on Quercus inflores- 

 cences and leaves) as a walled gall, covered round about by de- 

 rivatives of the normal epidermis, and the dainty gall -apple of 

 HeroatuB Rallarum (on willow leaves), disregarding ita morphologic 

 independence, are carnbial galls with the same development as the 

 one shown in figure 88, 



The description of the much ruptured gall of Lasioptera 

 pi eta , or of A ulax Hieraoii proves further that no; sharp bound- 

 ary may be draim "Between free and enclosed galls. I would like 

 finally to mention one more type of camblnl gall, in which, as 

 in the case of the walled gall of Hormomyia pillpcera . regulr.riy 

 defined portions of the new formation remain coverea oy the nor- 

 mal epidermis, while others become exposed. In figure JO i^ 

 shown a cross-section through an otherwise undertermxnD d pip- 

 tera-?) gall from the leaves of garinarium obtusi folium (Chryso- 

 balanes ) which will interest^ us in many ways, an i^J^^^^JJ' 

 cylindrical gall is produced by a local o^*§^owth of the meso- 

 phyll. Thus the strongly proliferating portion of ^^^ tissue 

 ruptures the epidermis which lies above it and by Showing fur- 

 ther, elevates it. Similar processes are repeated on JJ^; ?PP°- . 

 site side. We find here a tissue ring increasing relatively 

 weakly, In the development of which a circular rupture is formed, 

 the medial field of the epidermis remaining ^l^^^lJ^J^lf;^ 

 (222) level while the adjacent parts are raised by the o^^^gjowing 

 tissue ring. However, no new, real epidermal tissue is pro- 

 duced on the exposed parts. I know also of similar processes 

 in other g?\lls. .____-- 



^ Unfortunately, only herbarium material of this interesting 

 gall was at my disposal, (Herbar. Monacense), 



