36 THE THIRD YEARBOOK 



must solve in the process of growth during different periods of 

 the season. These problems are ahke to all the plants cultivated in 

 the garden, though differing somewhat in degree of importance. 

 They arise mainly from the plant's efforts to establish helpful rela- 

 tions (i) with sunshine, meaning both light and heat; (2) with 

 the soil for support and as a water reservoir, as well as for the sake 

 of small quantities of minerals; and (3) with the atmosphere as a 

 reservoir of oxygen and carbon dioxide as a food-supply. 



The clew to a solution of the problems falling under (i) and 

 (3) are found chiefly in a study of the leaves, including their mode 

 of attachment, position, relative size, shape, margin, arrangement, 

 structure, and movements. The problems involved in (2) are to 

 be worked out through careful observation of the root, beginning 

 when it leaves the sprouting seed. 



Certain movements of the plants were shown by the various 

 kinds of climbers that were trained up the walls of the schoolhouse. 

 The amount of work done by the plants was approximately calcu- 

 lated from data gathered from growing plants under special condi- 

 tions. Thus, the amount of water discharged through the leaves 

 was found by growing a plant in a wide-mouthed bottle closed 

 about the stem so as to prevent evaporation. By weighing at inter- 

 vals, placing the plant now in the sunshine, now in the shade, the 

 loss noted will be from transpiration, and the quantity of water 

 can be measured out so that the pupils may see it. Plants may 

 be weighed fresh, and afterwards dried and weighed again, then 

 burned, thus giving an idea of the water and of the dry solid, 

 and mineral matter built up during any given period of its 

 development. 



Again, the resources upon which the plant must draw for 

 materials were investigated through a study of the soil, rainfall, 

 temperature, slant and distribution of the sunshine. The gist of 

 the whole study under this head is (i) to see how the plants suit 

 their problems to the seasons : germination to the cool, moist April 

 and May ; the rapid development of the leaf and flower to the 

 long, bright, hot days of June and July; and the filling up of the 

 seed to the early autumn; and (2) to observe how they manage 

 to resist the encroachments of each other and to use each other, 

 as they all together take possession practically of the whole earth. 



