286 GALLS. 



SECTION XII. 



(158) GALLS. 



The official galls are abnormal developments on the twigs of 

 Quercus infectoria, Olivier, resulting from the puncture and 

 deposition of the eggs of Cynips Gallcc tinctorice, Olivier. 



The drug exhibits the following structure : 



(1) Epidermis, consisting of one or two rows of tabular cells 

 with brown, slightly thickened walls; in surface view these cells 

 are polygonal and isodiametric. 



(2) Parenchyma, which is differentiated into three distinct 

 layers, viz., an outer, middle and inner layer. 



The outer layer is somewhat hard and dense and made up 

 of rounded or polygonal cells with rather thick walls and 

 intercellular spaces; it is traversed by nbro-vascular bundles, and 

 many of the cells contain chlorophyll, or thin, colourless, trans- 

 parent, angular fragments of tannin. 



The middle layer is less dense and more or less pulverulent. 

 It is composed of large, rounded, polygonal cells with large 

 intercellular spaces, the cells thus easily separating from 

 one another ; they contain numerous fragments of tannin, 

 which give them a characteristic appearance. 



The inner layer consists of axially elongated, firmly adherent 

 cells ; they also contain tannin, but many contain single 

 crystals or rosettes of calcium oxalate. Towards the interior 

 this tissue forms a sclerenchymatous ring of irregularly 

 polygonal cells with thick pitted walls. 



Within the sclerencbymatous ring is a parenchymatous 

 tissue rich in starch, the grains of which are rounded and 

 exhibit a stellate hilum. 



The diagnostic characters of powdered galls are : 



(a) The abundance of tannin. 



(b) The sclerenchymatous tissue. 



(c) The xtarch grains. 



