38 PLANT LIFE ON THE FARM. 



may well be and often is the case that the injury to the 

 plant is compensated for by other conditions, and that, 

 in case of difficulties on both sides, it is wisest to choose 

 the least of two. 



The Stem and its Work. As the leaves, whatever 

 their form, are nothing but outgrowths from the stem, 

 and as no leaf exists except it be borne upon a stem, so 

 it would have been more in the natural order of things if 

 mention had been made of it before the leaves. As 

 regards the nutrition of the plant, however, the stem 

 plays but a secondary part, as compared either with the 

 root or the leaves, and on this account it may not inap- 

 propriately be considered after them. 



Botanically, any part of the plant that produces leaves, 

 or the representatives of leaves, is considered to be stem. 

 The root, inasmuch as it bears neither scales nor leaves, is 

 not stem; the "root- stock," inasmuch as it does bear 

 scales and leaves, is truly a stem, even though it may be 

 beneath ground. The long, creeping runners of "twitch" 

 (Triticum repens) are stems, so are the similar parts in 

 thistles and bear-bind (Convolvulus arvensis). The 

 bulbs of kohl rabi are clearly stems, for they bear leaves, 

 or the scars where leaves have once been. Beet roots, 

 mangels, radishes, turnips, parsnips, partake of the 

 nature of roots and of stems ; that is to say, their lower ? 

 tapering extremities are unquestionably roots ; their 

 thick upper end, surmounted by a crown of leaves, is as 

 unquestionably stem. There are anatomical differences 

 such as the presence of a root-cap, the absence of sto- 

 mata in a root, and differences in the mode of growth 

 between roots and stems, but they are not material to our 

 present purpose. It will be seen, from what has been 

 above said, that the definition of a stem (or of a branch, 

 which is only a subdivision of a stem), as that part of 

 the plant told off to bear leaves, admits of very wide dif- 



