8 GENERAL BOTANY 



2. Examine now a young thin branch of Bamboo, 

 a Balsam, or a Marvel-of-Peru plant. In the first 

 the leaf is divided into two parts the upper flat, 

 the lower encircling the axis. In all three where the 

 leaf or leaf-stalk joins on to the axis, the latter is 

 swollen and harder than the rest. This hard, swollen 

 part is called a node, and the part of the axis between 

 two nodes is called the internode. 



Now examine a plant of OCIMUM the Basil, or VINCA 

 the Periwinkle, or ZINNIA, or a branch of IXORA, 

 Coffee, Guava, or Pomegranate tree. The leaves are 

 placed not singly, as in grass or Bamboo, but in pairs, 

 one on each side of the axis. The part of the axis 

 whence they arise is again slightly swollen, so that 

 in these, too, there are distinct nodes and internodes. 



In the ordinary garden Begonia the leaves are all 

 attached to the plant singly, and there are again 

 distinct nodes and internodes. In the Sunflower, 

 CROTOLARIA, HIBISCUS and many other plants, though 

 the axis is not swollen where the leaves are attached, 

 these points are still called nodes, and the parts 

 between them internodes. 



Examine carefully a number of plants and notice 

 that we never find the leaves borne on one part of the 

 shoot in pairs and on another part singly. The 

 arrangement* is the same all over the plant, and 

 also in all plants of the same kind. It is, there- 

 fore, characteristic of the plant, and of the kind of 

 plant, and is of great importance in the study of 

 botany. 



When the leaves are borne singly, they are said to 

 be alternate, when in pairs Opposite, and when three 



