221 



throughout by them^. In many other galls also, as in the for- 

 mation o:^. vround-wood and giill wood, the increase of the inter- 

 cellular spaces containing secretions plr.ys an important nart;- 

 as for example, in many Pistacia galls (such as that of Pem- 

 phigus semilunularius and many others) . 



Less frequently, new forms 6f secreting cells and. tissues 

 occur in galls, which are not knovm in the anatomy of the nor- 

 mally developed host plants, I include among these a peculiar 

 gland, which I found in the interior of a Csmipides galls (on 

 Quercus V/islizeni) . This galls may he illustrated here as an 

 e::ample of a richly differentiated form (fig. 119). The se- 

 creting superficial cells are still to he mentioned;- such as 

 occur, for instance, in the ga5.1 produced hy Oynips argent e a 

 1 259} on Quer cue puh es cens ^ . in that of Andricus Sieholdii . in the 



Bassorah galls'^ etc. The galls of Cyhips Mayri a-opear similarly 

 "varnished)*. Unfortunately I could no longer recognize the 

 sttucture of the secreting cells in the dry material at my 

 disposal , 



Crystals of calcium oxalate are not generally found in 

 abundance in galls,- and w€l could verify the same scarcity in 

 many callus tissues. The entire absence of crystals seems to be 

 rare. Vanftevelde^ hag published some statements on the scanty 

 crystal content of those plant organs, which have galls.- Like- 

 wise, cases are not lacking, in which, we may find a rich crystal 

 formation in the galls. Kohl has emphasized the fact, that forms 

 rich in sclereids often contain crystals". In others the crys- 

 (260)tals occur as an accompaniment of the fibre -vascular cords. Cells 

 bearing crystals and united in radial rovirs are found in Tinctoria 

 galls and in others. In the products of Gynips Hedwigii ..and 

 Lryophanta verrucosa > certain' layers of the gall tissue are es- 

 pecially rich in crystl,ls (according to Kustenmacher) . I found 

 in the fagus gall (fig. 103) that all the cells which bear 

 crystals and are at an equal distance from the surface of the 

 gall had been united into a special layer, which lay on-the 

 boundary line between the large-celled outer tissue and the 

 small-celled inner one. The cells are often divided by exceed- 

 ingly delicate cross-walls; each division containing a single 

 crystal. In numerous galls we find that continuous layers of 

 crystal cells arise through the abundant but localized product ibn 

 of crystals, these cells layers, in many forms, lying in the 

 gall bark; in others, in the inner gall. 



The diversity of Eucaljrptus galls is surprisingly great. 

 The test^, which I had opportunity to investigate, lead me to 

 expect many an interesting result from a comprehensive treatment 

 of Eucalyptus galls from a develo-pmental " and histological stand- 

 point. 



2 ir 



Compare Hieronymus, Gallon aus Sudamerike und Italien. 

 Ztsehr. f. Entomol., 1892, Bd, XVII. 



^ j-HarMlch* Arch, d, Pharm. , 1883, p. 829. 



^ Investigations on fresh material w©uld lye very desirable - 

 the gall is abundant in Sicily. 



^ Bio'dr. tot de phys, der gallen, het aschgehalte d. aange- 

 tocte bladeren. Bot, Jaa.r'b, Dodonea, 1896, Vol. VIII, p. 102. 



^ Anatom.- physiol. Untersuch, d. Kalksalze etc. Marburg, 

 1889. 



