LESSONS IN BOTANY. 217 



Notice the position, shape and size of the buds; split a terminal 

 bud lengthwise and study carefully the relative position and the 

 form of the different parts; carefully take off some of the scales 

 with needles and note the character of their edges, and the differ- 

 ences between the apex arid base; note the secondary or new 

 buds, their form, position, etc. Compare the bud with a branch, 

 and observe whether the bud is a branch or not. Make a cross 

 section of a stem which is a half inch or so in diameter, and note 

 the central pith, the woody portion with its rings of growth, and 

 the bark outside the wood. Notice the fine lines radiating from 

 the pith to the bark, called medullary rays, and note that many of 

 them do not reach the pith. Notice also many scattered openings 

 from which resin exudes, they are resin ducts occurring both in 

 the wood and in the bark. Study the rings of growth noting the 

 difference between the inner and outer portions. 



The bark may be divided into three layers an inner, whitish, 

 fibrous layer, the middle green layer and the outer brownish por- 

 tion. Note the relative thickness of these layers and the resin 

 ducts in the middle one. Split a portion of the stem and study 

 the appearance and relation of the various parts in the longitu- 

 dinal as well as in the cross section. 



Notice the color, shape and texture of the leaves, note theapex, 

 edges, base and surface. Make cross sections and longitudinal 

 sections and notice the fibro-vascular bundles, resin ducts, the 

 green tissue and the epidermis. 



Take a cluster of male flowers and note that it is made up of a 

 central axis on which are arranged the short-stalked bodies, called 

 stamens. Each stamen consists of a flat scale, bearing on its in- 

 ferior surface two enlargements, the pollen sacs. Find a pollen 

 sac that has burst and note the location and character of the 

 opening, burst a pollen sac and notice the yellowish grains of 

 pollen that escape. The flowers on a very short stalk are crowded 

 on an axis forming a cluster called a spike. Notice that the 

 flowers each replace a "branch on the young shoot. 



Taking a spike of female flowers, notice the stalk or peduncle 

 by which it is attached to the stem, and that the spike is com- 



