EL3MENTS OF STRUCTURAL BOTANY. 3 



the plant. Ifc is nearly white. Then it is not of tho 

 same form as the part of the plant above ground. 

 It is made up of a number of thread-like parts which 

 spread out iu all directions, and if you examine one of 

 these threads through your magnifying glass, you will 

 find that from its surface are given off many finer 

 threads, called rootlets. These latter are of great im. 

 portauce to the plant ; it is largely by means of their 

 tender extremities, and the parts adjacent to these, 

 that it imbibes the nutritious fluids contained in the 

 soil. 



Whilst you are looking at these delicate rootlets, you 

 may perhaps wonder that they should be able to make 

 their way through the soil, but how they do this will be 

 apparent to you if you examine the tip of one of them 

 with a microscope of considerable power. Fig. 2 repre- 

 sents such a tip highly magnifiedr It is to 

 ij'ffe be observed that tlie growth of the rootlet 

 liljf ^^^^ ^°* ^'^^^^ 1-^'^^^ at tiie very extremity, 

 ^■■■^ b"t immediately behind it. The extreme 



^"^ " *^P consists of harder and firmer matter than 



Fig. 2. that behind, and is in fact a sort of cap or 

 thimble to protect the growing part underneath. As 

 the rootlet grows, this little thimble is pushed on firbt 

 through the crevices of the soil, and, as you may sup- 

 pose, is soon worn away on the outside, but it is as 

 rapidly renewed by the rootlet itself on the inside. 



Another difference between the root and the part 

 above ground you wiU scarcely have failed to discover : 

 the root has no leaves, nor has it any buds. 



You may describe the root of the Buttercup ^^ fibrous. 



