The detailed study of the buds is left for a separate lesson.
FURTHER STUDY OF TWIGS
The study in detail of various features is illustrated in the following:
Look closely at the leaf scars and describe them fully, as to shape, colour, and marks.
Do the scars look like fresh wounds, or are they healed over? Of what use to the tree is the healing of the scar?
We will learn later that the part of the twig between each pair of bands of rings represents one year's growth. How old is your twig? Who has the oldest twig?
Do all twigs grow at the same rate?
Who has the twig that had the most rapid growth?
To the teacher.—The bud at the end of the twig or its branches is called the end bud; there are two leaf scars underneath it. The buds along the sides of the stem are called side buds, the latter are smaller than the end bud. The bud situated between the stem of the leaf and the twig is in a sheltered position. This position also puts the bud close to the pantry door, for the plant food is prepared in the leaf. The leaf scars are yellowish-brown, or if they are the scars from the leaves of former years, are dark brown in colour. Each scar is shaped like a horse-shoe and tiny dots are found in the position that the horse-shoe nails would have. Even before the leaf falls, a layer of corklike substance has formed over the scar. This layer is a protection against the entrance of frost and rain and germs of fungi and it also prevents the loss of sap from the scar. The tiny oval pores, each as large as the point of a needle, are the breathing pores of the twig. The bands of rings are the scars of the scales of the end buds of successive years. This latter fact can be discovered when the bud is opening.