108 



FOUNDATIONS OF BOTANY 



obtained from maple trees in late winter or early spring, 

 and is boiled down for syrup or sugar, is still richer in 

 nutritious material than the water of the grapevine, while 

 the elaborated sap which is sent so abundantly into the ear 

 of corn, at its period of filling out, or into the growing 

 pods of beans and peas, or into the rapidly forming acorn 

 or the chestnut, contains great stores of food, suited to sus- 

 tain plant or animal life. 



EXPERIMENT XXI 



Rise of Water in Stems. — Cut some short branches from an 

 apple tree or a cherry tree and stand the lower end of each 

 in red ink; try the same experiment with twigs of oak, ash, 

 or other porous wood, and after some hours ' examine with 



the magnifying glass and with the 

 microscope, using the 2-inch objective, 

 successive cross-sections of one or more 

 twigs of each kind. Note exactly the 

 portions througl which the ink has 

 traveled. Pull off the leaves from one 

 of the stems after standing in the eosin 

 solution, and notice the spots on the 

 leaf-scar through which the eosin has 

 traveled. These spots show the posi- 

 tions of the leaf-traces, or flbro-vascular 

 bundles, connecting the stem and the 

 leaf. Repeat with several potatoes, cut 

 crosswise through the middle. Try 

 also some monocotyledonons stems, 

 such as those of the lily or asparagus. 

 For the sake of comparison between 

 roots and stems, treat any convenient 

 root, such as a parsnip, in the same way. 



Fig. 76.— a Catting girdled and 

 sending down Roots from tlie 

 Upper Edge of the Girdled Bing. 



1 If the twigs are leafy and the room is warm, only from 5 to 30 minutes 

 may be necessary. 



