VII.] LEAVES. 73 



exactly or nearly in the same vertical line, one above the 

 other. In the Tamarind the upper leaf will be removed 

 from the lower by but two internodes ; in the Orange and 

 Banyan, by either five or eight. When a single leaf is given 

 off at each node, the leaves are said to be alternate ; if a 

 pair of opposite leaves, they are described as opposite; if 

 three or more in a whorl, as verticillafe. 



The general arrangement of the leaves is materially 

 aftected by the extent to w^hich the internodes of the stem 

 develope. In the Chinese Primrose of gardens, and Ranun- 

 culus, we find the lower leaves springing in a tuft from the 

 short stock, owing to the non-development of the lower inter- 

 nodes; while in the latter the upper leaves are separated 

 from each other by distinct, and often long, internodes. A 

 parallel but more remarkable case we see in American Aloe 

 {Agave) and Adam's Needle {Yucca), much cultivated in 

 India, in which plants a succession of (really alternate) 

 leaves are given off from a very short stem or stock, the 

 internodes of which are not perceptibly developed. This 

 is continued until the approach of the flowering season, 

 when the stem suddenly begins to lengthen out, and the 

 leaves gradually decrease in size to mere scales. In Crinum 

 and Tacca they cease altogether for a long interval, leaving 

 the flower-stalk naked. In most deciduous trees, the inter- 

 nodes from which foliage-leaves are given off are tolerably 

 uniformly developed, but in Pine and Deodar an anomalous 

 condition occurs. In these trees there are two kinds of 

 leaf — one a small, membranous, brown scale-leaf- the 

 other, a green, needle-like leaf The needle-like leaves 

 are arranged in tufts of 2, 3, or 5 in Pines, or in many- 

 leaved clusters in the Deodar, in consequence of the non- 

 development of the internodes of the excessively short 

 branches which bear them. That these tufts really arise 



