364 



THE VASCULAR TISSUES AXD TRANSPIRATION. 



their transpiring leaves. In very many lianes the cavities of the conducting vessels 

 can be plainly seen with the naked eye. This is the case, for example, in the cross- 

 section of the liane represented in natural size in fig. 95 5 . A diameter of J mm. is 



Fis- 95.— Uanes. 



1 Portion of tnc nem of a tropical .1 rixt'rfochia. a Cross section of a liane-iike Aristolochia. « Menispermum Carolinianum. 

 * Cross section of the twining stem of Memmermum (magnified). * Portion of a liane (probably au Asclepiad) gathered in 

 a tropical forest; nat size. 



not at all rare in passion-flowers and aristolochias, and, generally speaking, in mi -t 

 twining and climbing plants: whilst in many lianes the conducting tubes have 

 even been observed to be 0" mm. in diameter. 



