144 THE ROOT SCALES. ["LECT. IV. 



bably, as has been suggested, to enable it to resist 

 drought ; and not at all resembling the tubers of 

 the Potatoe and other similar tuberiferous roots, 

 which are annual productions; and, as I shall pre- 

 sently explain to you, belong nearly as much to the 

 stem as to the root. 



Having finished the observations I had to offer 

 on the external characters of roots, our next ob- 

 ject is to examine the APPENDAGES of these organs ; 

 which are as fixed in their forms as the roots 

 themselves, and are, consequently, taken advan- 

 tage of in describing plants. All the appendages 

 of roots may be arranged under the following 

 genera: I. Scales; 2. Suckers; 3. Knobs or 

 Tubers ; and 5. Bulbs. 



1. SCALES are in many instances the remnants 

 of leaves which have decayed and fallen, as has 

 already been explained (p. 133). They more fre- 

 quently occur in roots which assume a horizontal 

 direction ; in which cases the lower part of the 

 stem which is in contact, or nearly so, with the 

 soil, gives off lateral rootlets, immediately above 

 the point of attachment of the decayed leaf ; and 

 these, dipping into the ground, drag that portion 

 of the stem under the surface of the earth, where 

 it gradually acquires all the characteristics of a 

 root. There are, nevertheless, some roots originally 

 furnished with scales, and very few or no lateral 



