16 



A tangential section, (fig. 118 Pl. X) shows the présence of 

 some alcaloid in the vasal parenchyma, while a longitudi- 

 nal section fig. 119. Pl. X) shows large quantities of it in 

 the cribral -parenchyma. 



lb. The Starchsheath and the t issues outside of it. 



This is synonymous with primary bark. The inner lay- 

 er of it, the starchsheath, contains no alcaloid (c. fig. 117 

 Pl. X. fig. 120, 122 Pl. XI) ail other cells with the 

 exception of those which contain oxalic acid, the gummi- 

 harzschlauche, and the epiderm, do. 



2. The sccondary t issues. 



2a. The Wood. 



The cambium generally contains no alcaloid but some- 

 times one meets with it there. It seems to me that it is 

 only found when the cambuim is inactive, yet I am not 

 quite sure of this. 



As soon as the cambium cells have entered on a pe- 

 riod of comparative inactivity preparing themselves so to 

 speak for the coming changes in their function they con- 

 tain alcaloid no matter wether later on they will become 

 vessels, woodfibres or whatever else. 



The adult woodvessels never contain any alcaloid, the 

 adult woody fibres very rarely (c. fig. 128 pl. XIII at x). 



The cells of the medullary rays and their plate-like 

 prolongations do contain alcaloid and starch as do the 

 woodparenchyma- cells even in the eldest layers of bl anches 

 of a diameter of 1 decimeter (older ones were not inves- 

 tigated in this respect) most alcaloid is found in the cells 

 of the medullary rays less in those of their prolongations 

 and but little in the wood- parenchyma (c. fig. 126, 127, 

 Pl. XII and fig. 128 Pl. XIII). 



