18 ART. 6. — Y. YENDO : 



interesting that the bundles containmg SO4CU are regularly situated 

 on the upper side of the horse-shoe shaped vascular bundle groups 

 in all tlie palmate veins. Many veinlets are given off from the 

 palmate veins and terminate in the parenchymatic mesophyll, 

 forming a network which is often blackened, due to the action of 

 SO.Cu (PI. II, Fig. 1, D). 



The lithium injection was made into the pulvinus of a leaf of 

 Magnolia hypoleuca (exp. 4, PI. I, Fig. 3). The point of injection 

 was situated on one side of the pulvinus. The result obtained was 

 that lithium was found in only one half of the blade. This shows 

 that a vascular bundle in the pulvinus runs through the midrib 

 and branches off as veins and veinlets only on one side of the 

 blade, but not on the other. A similar case occurred in the ex- 

 periment with the pinnate leaf of Aspidium lacsrum (exp. 39, PI. I, 

 Fig. G), whose vascular bundles are separated one from another by 

 the interjacent ground tissue of the petiole. I observed also in the 

 experiments on woody plants that lithium was detectable only in 

 the branches belonging to the injected side, but not at all in 

 those of the opposite side. 



Thus, by the above moans, the course of vascular bundles can 

 be determined. 



X. Summary. 



1. The rate of conduction of an injection varies according to 

 tlie nature of the substance ; among the substances used in my 

 experiments, lithium nitrate is most easily conducted, SOiCu and 

 eosin less easily, aniline violet the least. 



2. The injected substances are mostly carried to that part 

 where the transpiration is going on naost actively. 



a. Lithium, when injected into the stem, is found more in 



