ARBOR DA Y MANUAL. 



335 



HOW AN APPLE TREE GROWS. 



WHEN a young seed begins to grow it starts with one little cell. This cell 

 is a kind of round bag, or tiny bladder. It is hollow, and has in it a 

 sort of jelly. 



Those who study plants can with their microscopes watch just how the 

 young seed grows. When first they observe the tiny sack, or cell, it is not 

 larger than the point of a pin. They can see it grow larger, but even when it 

 is full grown it is no larger than the dot over this letter /'. 



Next, they can see a very thin wall thinner than the thinnest paper grow- 

 ing inside of the little cell. This wall, or partition, grows quite across from 

 one side to the other, making two little cells of it. 



After this, a partition grows in each of these two cells, making four. And 

 so the seed goes on growing, by each of the cells dividing into two or more. 



All plants grow in this way. But each plant will grow according to its own 

 seed. The seed of a turnip will begin to grow with one cell, and then make 

 cell after cell, with all the cells packed pretty close together. But all these 

 cells will grow together in such a way as to make a turnip-plant. An acorn 

 will grow in the same way ; but all its cells will grow together in such a way as 

 to make an oak tree. 



Think of a large apple tree. First it began with a tiny cell in the bottom of 

 a pistil of an apple blossom. Out of this cell grew two other cells. Then out 

 of them grew more cells. And so they kept on until the whole seed was ripe. 



Now here is something very curious. All those little cells in that little apple 

 seed grew in such a way that they actually made a little apple tree inside of 

 that little seed. There they made a minute pair of leaves, and a minute point 

 of a root. When the tiny cells had their tiny plant completed the seed was ripe. 



The apple fell from the tree, the seed entered the ground, and in the spring 

 the wet in the soil below, and the heat from the sun above, burst open the seed. 

 Then out came the little point of a root, and, not liking the light, grew down- 

 wards into the ground. 



But while the little point of a root was doing this, the little pair of leaves, 

 folded up in the seed, also began to grow, and, loving the light, pushed their 

 way up where they could feel the warm sunshine. 



There the little pair of leaves spread out. Then up between them grew the 

 little stem. Then more leaves came out ; and still the stem kept pushing up, 

 and still more leaves kept coming. 



Moreover, while the plant was growing above ground, the little root under 

 ground was branching and growing larger, and with all its fine young hollow 

 hairs was sucking up the water from the soil, to go up to the leaves, which 

 took in the air that some of it might mix with the sap to make the very stuff 

 that forms the little cells. 



The roots and leaves work together to build up the plant. The roots take 

 water from the ground ; but that alone would not make cells. The cells must 

 have carbon ; and this the plant obtains mostly from the air, by breathing it 

 through the leaves. 



