lo Plant Morphology. 



A small axillary bud occurs at the first node below the 

 terminal bud. 



Notice the scar of the leaf with which the modified stipules be- 

 long. This leaf never developed and only a faint trace of it re- 

 mains. The line of union between the stipules passes from this 

 rudimentary leaf-scar over the obtu.se apex of the bud, to the 

 axillary bud on the other side of the stem. 



Carefully separate the .stipules along the line of union. 

 Within will be found a minute leaf (in some of the buds, the 

 third pair of stipules, instead of the second, is the first to bear a 

 leaf) with blade, petiole, and stipules. The stipules of each 

 leaf enclose the whole of the next leaf above. Thus the stipules 

 of every leaf form a protection to the next above, and, in fact, to 

 all the leaves above. 



The non-development of the leaf at the node where the winter 

 bud is formed, indicates just where that bud was formed each 

 winter during the growth of the branch. 



The internodes are much shorter near the winter bud than in 

 any other part of the year's growth ; as a general rule branches 

 are developed only at the two or three nodes just below the winter 

 bud. 



Notice that the bark on a branch changes its color when about 

 three years old. 



The lenticles which are not abundant, have their office per- 

 formed by longitudinal ruptures in the epidermis. These rup- 

 tures generally occur through one- or more lenticels. 



Sketch a branch enlarged, with terminal bud dissected to show 

 parts enclosed. 



II. BRANCH OF COMMON LOCUST {Robinia Pseudacacia). 



The terminal bud dies at the end of a season's growth. The 

 branch is prolonged by a lateral bud which takes the place of the 

 terminal one. This tree as well as the Sumach and Blackberry 

 are examples of indefinite annual growth. 



The buds are all naked. The stipules which in the Tulip-tree 

 are modified to protect the growing point against extremes of 

 temperature, here assume the form of spines. 



Note that the growing point although without bud-scales, is 

 protected by the corky tissue formed at the leaf scar, and still 



