36 The Farm Woodlot 



species with which we are interested at present, there 

 are only two means of distribution : the wind and the birds. 

 The fleshy fruits, such as cherries, hackberries, red cedar 

 berries, and the like, are eaten by the birds and dropped, 

 often far from the tree on which they grew. The heavy 

 nuts can only roll or be carried short distances by squirrels. 

 All the others are supplied with some means to facilitate 

 wind transportation, as tufts of hair, wings, leaf attach- 

 ments, and the like. 



LIFE HISTORY OF A TREE 



With the above description of the tree and its parts in 

 mind, it will be easy to follow out a brief sketch of its 

 life history. When the seed is first placed in the ground, 

 it begins to absorb moisture. This softens the outer 

 coating of the seed and causes the fleshy portion within 

 to swell. Moisture and warmth start the growth in the 

 embryo of the seed, the real germ of life. The covering 

 splits, the primary leaves or cotyledons appear above the 

 ground and the root grows downward. The plant at 

 this stage feeds on the fleshy part of the seed, the endo- 

 sperm. At this stage it is almost impossible for any one 

 but an expert to distinguish the different species, since 

 the cotyledons do not, in many species, in the least 

 resemble the mature leaves. The arbor vitae and the pine, 

 for example, are hardly distinguishable the first season. 



The plant is established on an independent growing 

 basis if the root strikes readily into mineral soil, but if, 

 through any difficulty the endosperm is exhausted before 

 the root takes hold, the seedling shrivels and dies. The 

 different species vary greatly in their habits of growth in 



