WEST MICHIGAN FRUIT GROWERS' SOCIETY. 167 



zeal to be doing something to promote their growth, and increase their fruit- 

 fulness. 



Much of what is really known concerning the office of roots is determined 

 by analogy. All animal creatures inspire or respire or perspire and in that 

 act, or by it, thoy retain life and vigor. They also assimilate nutrition and 

 come to perfection in the degree of its plenitude. Animal foods are various 

 in character, to suit the wants of the various organisms demanding "daily 

 bread." Even the sponge — that connecting link between the animal and the 

 vegetable kingdom — is known to suck the sea water through the many chan- 

 nels of its substance and eject it in streams from cone-shaped mouths at its 

 upper surface. So we know that along the roots somewhere, and possibly 

 over their whole surface, are little mouths through which the plant receives 

 the pabulum upon which its structure is built. As the nectar of the sea water 

 nourishes the sponge, so.the juices of the earth — in meagre supply or abund- 

 ance — are sucked up and sent along the sinuous channels of the woody fiber 

 until, strained and distilled of its earthy salts, to be given up as food, the 

 pure, surplus waters as set free in vapor from the leaves. 



THE PROCESS OF NUTRITION. 



• 



To intelligently furnish that aid to plant growth which we desire, it is 

 necessary for us to know in what manner and under what conditions the 

 plant receives and requires the nutrition to be presented. The roots evident- 

 ly do not come up like lambs to a trough of corn and devour solid particles 

 of food, so that dumping a pile of manure about the trunk of a tree is in no 

 sense furnishing adequate supplies of food. If this is done the day the tree 

 is set out, two very important principles in plant growth are subserved: 

 The percolating juices which the rains bring down in the earth, furnish the 

 first protruding fibers of rootlets with a rich renewal of growth, and also con- 

 serves by its cool covering the moisture already found in the soil. Every tree 

 planter has noticed that before any evidence of life is present in the branches 

 of the young tree he is setting, there will be little white hair-like radicles 

 coming from under the bark where the roots have been severed, and these 

 doubtless furnish to the tree its new life and growth. And so at every 

 recurring period of growth new roots form first and this new formation is 

 determined by the conditions of soil which warrant a continued supply of 

 food within easy reach. As the tree spreads its branches wider, so the roots 

 make constant incursions and invasions into the unexplored strata, wider and 

 deeper and constantly asking of the soil what it can do for the parent tree. 

 When rich deposits of food are found, there the white radicles protrude in 

 force and the little spongioles at the ends absorb the juices, which are for- 

 warded by little elevator tubes to the great laboratory of the leaves, where it 

 is transmuted into fragrance, fermented into acids or fused into sweets, 

 becoming blossom and leaf, and ending in fruitage at last. 



THERE ARE TWO CLASSES OF ROOTS, 



the primary or true and the secondary or adventitious. The primary root is 

 formed by the direct elongation of the radicle. The secondary root does not 

 proceed from any definite point, and its development depends upon favorable 

 external circumstances. When the conditions of soil are naturally favordble 



