5(5 . OF THE ROOT. 



The limits between a bulbous and tuberous root are not easily 

 defined ; the solid bulb seems to partake of the nature of both. 



Bulbs usually die after the blossoming of the plant ; "but new 

 bulbs are often formed from the base or sides of the original 

 bulb, which in their turn produce plants. This is the fact with 

 respect to the orchis tribe ; in which every year one bulb or 

 tuber dies, and the other throws out a new stem; by this means 

 it changes its position, though very slowly, since it takes but 

 one very short step each year. The production by means of 

 bulbs, is only a continuation of the old plant, while by means of 

 the seed a new plant is brought forth. 



This is an important distinction ; and it is observed that in 

 process of time, a plant continued by means of reproduction, 

 whether by bulbs, grafting, or any other manner, ultimately 

 dwindles and degenerates as if worn out with old age, and it 

 becomes necessary to renew its vigour by producing a young 

 plant from the seed. This is the case with the potatoe, which 

 is ordinarily produced from the root ; but the farmer often 

 finds his stock de'generated, and is obliged to provide himself 

 with new roots produced from the seed. 



The specific character of plants is sometimes taken from the 

 root, and in some cases the specific name ; as SOLA.NUM tubero- 

 sum, the potatoe, and RANUNCULUS bulbosus, the bulbous ra- 

 nunculus. The tuberous and bulbous roots distinguish those 

 species from all others of the families Solanum, and Ranun- 

 culus. q 



The forms of roots are so various, that it is impossible to give 

 names to all ; even in the same species of plants, the root pre- 

 sents many varieties of form. In the potatoe, for example, wo 

 see some roots round, and of an even surface, others, long or 

 oval, and some very knobbed and irregular ; but yet amidst all 

 this variety there is a prevailing uniformity, and we can usually 

 at one glance distinguish a potatoe, by its form, from all other 

 vegetables. It might, at first, have appeared as if there could 

 be little interesting in the consideration of roots, which are des- 

 titute of that symmetry of parts and liveliness of colouring, 

 which is exhibited in other organs of the plant. We find, on 

 casting a rapid glance over the face of the earth, that all this 

 variety in the form of roots is not without its peculiar use. 

 Mountains being exposed to winds, we find them covered with 

 plants which have branching roots with strong and woody 

 fibres. These, fastening themselves into the clefts of rocks, 



Difference between the continuation of plants by bulbs, &c. and by raising 

 from the seed Specific character and name taken from the roots Roots of the 

 same species sometimes vary in form Utility in the variety of form in roots. 



