soon as the vascular bundle- initiais become differentiated 

 alcaloid is met with evei ywhere except in thèse initiais 

 and in the epiderm. On a somewhat older stage like fig. 

 93 Pl. VI wc see, using a magnifying power of about 17 

 times, no alcaloid in the primai y vascular bundles ( 1 J while 

 lots of alcaloid is seen in the primary bark (not in its epi- 

 derm however) and it is further observed that the quantity 

 of alcaloid in the pith decreases in a direction from the 

 periphery towards the center. Later on, when the pith 

 dies the alcaloid disappears from it. 



For conveniencc's sake we will treat separately of the 

 tissues inside of the starchsheath and of the starchsheath, 

 and of the tissues outside of it combined. Tins cutting 

 up of the stem into two parts is perfectly legitimate as the 

 starch-sheath is the innermost layer of the primary bark. 



la. Tissues inside of the starch-sheath. 



Proceeding from the exterior towards the interior we can 

 distinguish the pericycle consisting of one or two layers of 

 cells containing alcaloid. Then we meet with a ring of 

 vascular bundles in which the cambium begins to divide at 

 a very early stage. Between the différent vascular bun- 

 dles small bands of parenchyma, the pithrays, are seen, thèse 

 contain alcaloid both in the part between the phloem-bun- 

 dles and that situated between the xylem-bundles. In the 

 région of the cambium they contain no alcaloid, nor does 

 the intervascular cambium (c. fig. 117 PI X). 



The cambium contains no alcaloid wherever it may be 

 situated (c. fig. 120, 121 Pl. XI, fig. 124, Pl. XII,fig. 125 Pl. 

 XII); as soon as the parenchyma — cells formed by the ac- 

 tion of the cambium, enter on a period of rest they do con- 

 tain alcaloid however. 



(!) In some of its parts there is alcaloid, but too littlo tobo observed at 

 this slight enlargement. See further down. 



