Essential parts of the Young Plant. 35 



Process of Germination of the Seed. 



132. The seed contains the germs of the first growth of the future 

 tree in an embryo, and the cotyledmis or seed-leaves that will first ap- 

 pear. In the conifers, such as the pines, spruces, and cedars, there 

 are several of these cotyledons, but in most other trees that we shall 

 have occasion to notice there are two. 



133. When living seeds are properly exposed to darkness, moist- 

 ure, air, and warmth, they will sprout and grow. In this process, 

 there comes out from the embryo a root, or radicle, which descends 

 into the soil iu whatever position the seed may chance to lie, while 

 the cotyledons or germinal leaves seek the air and the light, forming 

 the plumule or stem of the plant. 



134. The time required for sprouting varies from a few hours to 

 a few days, and in some cases it does not occur until the next 

 season. The process may sometimes be hastened and assured by 

 previously soaking the seeds, and in those hav- 

 ing hard shells by scalding, as elsewhere more 

 fully described. 



135. The cotyledons of the acorn (a) are 

 made up of a multitude of small cells, filled 

 ■with a kind of starch, which performs an office 

 quite analagous to the albumen of an egg, and 

 is sometimes so called. It differs, however, 

 from albumen as found in the egg, and in the 

 serum of the blood, and is a form of proteine, 

 not forming a part of the tissues, but contained 

 in cells ; as a thin jelly mingled with the juices. 

 In other forms it is called gluten, and, with 

 starch, it forms the principal bulk in grains 

 and seeds. 



136. This, absorbing moisture from the soil, 

 and having access to the air and carbonic acid 

 gas in the soil, is changed into sugar, which is 23. An Acorn givin? out 

 soluble in the juices of the young plant, and by l^le^'"""""^" °"'^ ^^'^■ 

 the time that this supply is spent, the roots 



have got well started, and the young tree has all the elements of 

 life that it requires for future growth. 



