MA.IZE STEM 165 



III. Cut successive, thick transverse sections through 

 a node : treat them with strong potash ; or, better, 

 soak them for twenty-four hours or more in dilute 

 potash : mount in glycerine, and examine with a low- 

 power. 



Observe that the vascular bundles here form a dense 

 plexus, in which may be recognized 



1. Branching, and anastomosis of the bundles of 

 the main axis with one another, at the base of the 

 internode. 



2. Entry of the bundle-system of the leaf- trace, and 

 of its axillary bud, into the main axis, in which the 

 bundles at first pursue an irregular horizontal course. 



3. Anastomosis of these bundles with those of the 

 main axis. 



The result is a thorough intercommunication of 

 the several systems of bundles, one with another, at the 

 node. This modification of the type of bundle-arrange- 

 ment characteristic of the Monocotyledons is the rule 

 in those of the group which have long internodes. 



Observe that the structure of the individual bundles 

 at the node differs from that in the internode, the 

 change depending upon 



1. The sheath of sclerenchyma being relatively 

 larger. 



2. The irregularities of vascular arrangement result- 

 ing from the fusion of bundles. 



IV. Cut longitudinal sections through a node in 

 planes parallel to the median plane of the leaf and 

 axillary bud : treat as above, and observe 



1. The branching and fusion of the longitudinal 

 bundles of the internode at the node. 



