STROXO DNLXK JXD TOBACCO SMOKE. If) 



Nature has made for the young phiiit, until it is uLle 

 to assimikte other food. 



The diagram (Phite 2, fig. 9) represents, on a much 

 enhirged scale, a section of the young plant at the fore- 

 going stage of its growth, cut open vertically, the leaves 

 being represented by lines. There are six of these, 

 exclusive of the cotyledonary leaf (c), and the figures 1 

 to 6 represent the order of their growth. No. 1, the 

 first formed leaf, has been superseded in growth by 

 No. 2, and has then died down ; No. 2 in its turn will 

 be outgrown by No. 3, and will then die down ; and so 

 with the others, the point from which they grow being 

 a dense mass of living vegetable tissue. I shall have to 

 return to this part of the subject when treating of the 

 stem ; in the meantime let us examine the rootlets of 

 the plant. These are so delicate, that they may be 

 placed bodily on the stage of the microscope in water, 

 and pressed down under a thin glass cover. They will 

 be found to consist of a mass of minute elongated cells, 

 with very thin walls ; in the centre of the mass spiral 

 and other vessels are forming. But at the point of each 

 rootlet is a peculiar conical body (fig. 10) called the 

 root cap, which is supposed to assist materially in 

 absorbing; the salts and other matters held in the soil 

 for the nourishment of the plant. This function is 

 denied to it by many, but it is clearly proved that if 

 these caps are broken off they are never reproduced 

 and the rootlets wither.* 



* Scbleidi-n's Principles of Botany, p. 220. 

 C 2 



