11 Jt'NE, 1917. J Apple Culture in Victoria. 



339 



they, or at least some of them, particuhirly when grown under tliose soil 

 and climatic conditions, which are apjiarently favorable to the develop- 

 ment of this disease, are influenced by the stocks on which they are 

 worked. 



This is a matter which requires much observation and experiment, 

 and one in which the orchardist should play a prominent part. But in 

 order to do this satisfactorily a good knowledge regarding the struc- 

 tunil botany of the apple tree is essential. 



Tlien l)y understanding the functions of the various organs of the 

 tree, and with a knowledge of osmosis, the fruit-grower will find himself 

 equipped with information which will be of considerable assistance to 

 him in connexion with his study of the growth of the tree, particularly in 

 relation to soil cultivation, manuring, drainage, irrigation, pruninc:;, &c. 



> iO 











Plate 96. — Highly magnitied section of epidermis of a Jonathan Leaf, 

 showing stoma ta. 



Functions of the Roots. 



The roots have two offices to perform, viz., to hold the tree firmly in 

 the soil that it may resist the wind, storms, &c., and to supply it with 

 liquid food. 



During the periods of growth the roots are constantly forcing them- 

 selves downwards and outwards through the soil in search of the food 

 they require. 



"When the points of the leading roots of the Northern Spy variety 

 have extended beyond a few inches in length they invariably send out 

 numerous lateral root hairs which absorb sap, and act as tributaries to 

 the main ehatmels. 



The numerous root hairs, which branch off from the main roots in 

 the various directions, are composed of extremely soft, spongy, delicate 



