24, OUR WOODLAND TREES. 
Between these extremes there are varying shades of 
colour. The surface of the seed coat, too, is some- 
times smooth and sometimes rough, sometimes 
plain and sometimes externally ornamented by 
beautiful markings. 
Passing now to a consideration of the living 
germ or plantlet, we find that this consists of a 
little body made up of three principal parts— 
namely, the radicle or germ of the future root, 
the plumule or germ of the future stem—and 
all that rises above ground supported by the 
stem—and the cotyledons, or ‘seed leaves,’ 
as they are popularly and beautifully styled. 
Here it should be explained that the part last- 
named may in an individual plantlet be single or 
double—a cotyledon or cotyledons; and the dis- 
tinction serves to divide into two groups all the 
flowering plants in the vegetable kmgdom. Those 
whose seeds are furnished with but one cotyledon, 
or, if with more than one, having them placed in 
alternation on the embryo, are termed Mono- 
cotyledons. Those with cotyledons placed oppo- 
site in the seed, and in number consisting of two 
or more—the number is generally two—are termed 
