28 THE GROWTH OF THE TREES. 



from the fact of their having two cotyledons in the embryo, 

 and among those that have more than two, which is a peculiar- 

 ity of the pine family. {Plate IV.) 



We can hardly fail to notice when looking at a young plant- 

 let with what perfect symmetry its leaves are arranged on the 

 stem, and as it continues to grow much of this same order is 

 maintained even should it be become the largest tree. It is 

 not strange then that branches show much of this same sym- 

 metry of arrangement ; for they follow precisely in the wake of 

 the leaves. Early in the summer, in the axils of the leaves and 

 at their upper sides, we see that buds begin to appear. They 

 are axillary buds, and are the progenitors of branches. When 

 they begin to grow they pursue the same course of develop- 

 ment as did the first stem which sprang from the embryo with 

 the little buds between the cotyledons. In the same way they 

 grow, joint upon joint ; each one elongating and throwing out 

 leaves at its summit. Other buds are formed in the angles of 

 their leaves and they also become leaf-bearing branches ; and 

 so is this simple process repeated while the structure of the 

 tree is building. The only difference between the growth of a 

 branch and that of a germinating plantlet is that th^ branch is 

 embedded in the larger stem and draws from it its sustenance, 

 while the young stem had to forage for itself and strike out 

 roots into the ground. It sometimes happens that buds begin 

 to grow shortly after they first appear, and again they lie dor- 

 mant and hidden until the spring of the next year. 



Little in the life of the tree is more interesting than the ten- 

 der care Nature bestows on these young offsprings. Her wis- 

 dom is very great ; for should the delicate buds be ruthlessly 

 exposed to sudden changes of temperature, or to intense cold, 

 they would assuredly perish, and the next season no branches 

 would be forthcoming. The button-wood and locusts illustrate 

 to us one unique way of guarding leaf-buds from all harm. 

 Apparently the base of the leaf-stalk is swollen ; but when 

 it is detached from the stem and examined, it is found to be 



