TREES GROWING IN SANDY SOIL. 245 



nut drops into the ground and begins to germinate it does not 

 send up at once two cotyledons from the summit of itshypocotyl. 

 They, in the husk, have become so thickened as to have lost 

 their power of acting as leaves, and they occupy nearly the whole 

 of the seed. Instead, therefore, of growing themselves, they 

 supply to the plumule, or little bud which lies between them, an 

 abundance of nourishment. For this reason when it sends up 

 the first joint of its stem, the first leaves that appear on it are 

 imperfect, often little more than scales. The true cotyledons 

 have remained below. [Plate VI.). 



BLACK OAK. QUERCITRON. YELLOW-BARK OAK. 



{Plate CXXXIII.) 

 Quircus velutlna. 



Between the black oak and the scarlet oak there are certain 

 differences in colour which may aid many to distinguish them. 

 It is true that at times they are dissimilar in leafage, but again 

 the black oak is so very variable that some of its forms are 

 nearly identical with those of Quercus coccinea. 



The kernel of its nut is bright yellow and smaller than that 

 of the scarlet oak, which is white. But unfortunately the 

 acorns mature in September and October only, so during the 

 early part of the summer we must seek out some other unchang- 

 ing difference between them. Again we are aided by colour. 

 The bark of the black oak is a dark brown, or nearly black, and it 

 is broken into close scales. A still more poignant difference 

 is that its inner bark is deep orange, never reddish or grey. 

 In the spring its leaves are red, and they turn when the 

 tree blooms to a silvery green. They are rich red or russet 

 in hue in the autumn and quite without the vivid touch of 

 colour which is the chief charm of the scarlet oak. 



The tree grows with a narrow, open head to a height of from 

 seventy to eighty or even a hundred feet. It is never as 

 stately as the red oak. In the coloured plate the leaves are 



