HIPPURIS STEM 69 



dermatogen and periblem, the plerome taking no part in their 

 formation. Also that the vascular system of the stem is 

 already developed at a higher point on the axis than that of any 

 of the leaves. We have thus an instance of cauline vascular 

 bundles, that is such as are proper to the stem, as distinguished 

 from common vascular bundles, which terminate at their upper 

 extremities in the leaves. 



