106 



Plant Physiology 



and the like - - permit of diffusion, and in the end the 

 demands of each cell govern the flow toward that cell. 



63. Fibrovascular bundles. - - If freshly cut (under 

 water) shoots of the jewel- weed, sunflower, Indian corn, 



canna, or other convenient rep- 

 resentatives of monocotylous and 

 clicotylous plants are placed in 

 a solution of a dye such as eosin 

 or fuchsin, the stain will pass 

 upward through the conducting 

 system of the plant, and the 

 paths of conduction may thus be 

 made evident, although there is 

 sometimes a slight lateral diffu- 

 sion tending to obscure the defi- 

 nite channels. 



It will be recalled that mono- 

 cotylous plants are characterized 

 by stems in which the vascular 

 strands are commonly distributed 

 in irregular manner throughout a 

 ground tissue called 

 B parenchyma, as in corn 



or sorghum. A hand 

 section will show at a 

 glance, this distribution 

 of the bundles, and it 

 * T ,. is also strikingly 



FIG. 34. Vascular system of Clematis, 



apical portion of the stem : longitudinal brought Ollt by break- 

 view of stem and leaf trace bundles (A), mo . a c | r y corn stalk 

 and cross-section of internode (B). 

 [After De Bary and Nageli.] through an internode 



