14 



cellwall. This phenomenon is explained by the fact that 

 the iodine solution was transported through the vascular 

 bundles and from there diffused into the surrounding tissues. 



Tha solution consequently rea^hes at the cells inside of 

 the bundle-ring the outer wall fïrst, at those outsîde the 

 inner wall first and précipitâtes the alcaloid at the point 

 of entrance. This is shown plainly in fig. 111 and 112 

 Pl. IX. The sraall bundles at t he upper si le of the leaf- 

 stalk conduct the water also as is seen fro'n the f act that 

 the half-moonshaped precipitate is formed at the cellwalls 

 turned towards them (c. fig. 11.0 pl. IX). In the su called 

 ..Gummiharzschlàuche" of de Bary I have been unable to 

 demonstrate the alcaloid, yet there may be sone in it, 

 as the large quantities of tannins andiosin in their inte- 

 rior make microcheinistry unreliable here. 



6. The budsccfes. 



The budscales of Cinchona are peculiar on account of 

 the spécial glands présent on their interior side which 

 glands secrète a rosinous substance. They eonsist of an 

 internai bundle of elongated cells covered by a layer of 

 cells which reminds us strongly of animal epithelium (c. fig. 

 89 Pl. V.) Thèse epithelial cells contain no alcaloid, the 

 central cells do. Considérable quantities of alcaloid are met 

 with in ail parenchyma cells of the budscales, the epiderm 

 and hairs contain no alcaloid (c. fig. 89. Pl. V.) apparently 

 the plant is not very economical as far as its alcaloid is 

 concerned as the leafscales, which have been dropped con- 

 tain alcaloid yet. (c. fig. 92. PI Y.) 



B. Tue stem. 



1. The primary stem- tissues. 



As long as no trace of différent iation is apparent in the gro- 

 wing point (c. fig. 89 Pl. V.) no alcaloid is found there. As. 



