356 



CONDUCTING SYSTEM 



vessels. The leptome-tissue of Monocotyledonous bundles also exhibits 

 considerable variety as regards the nature and arrangement of its con- 



Fig. 144. 

 Vascular bundle from the sheathing leaf-base of Musa paradisiaca (T.S.). 



stituent elements ; it is, however, always principally composed of sieve- 

 tubes and companion-cells, while a small amount of parenchymatous 

 tissue (including cambiform cells) is also present, especially towards the 

 Hanks of the bundle. Kny has shown that, in the petioles of many 

 Palms, the protective sheaths of fibrous tissue are produced inwards in 



