268 



PEOPAGATION BY KNAUES. 



portion is left adhering to them, and, being planted, grow into 

 young Olive-trees. Of these we have no further account ; but 

 it is evident that the uovoli are no other than our knaurs 

 (Fig. XXXVI.), already spoken of under the name of embryo 

 huds; concretions found in the bark of many, and probably of aU, 

 trees, and supposed to have been adventitious buds developed 

 in the bark, and, by the pressure of the surrounding partSj 

 forced into those spheroidal woody masses in the shape of which 

 we find them. They often present an oblong or conical form. 



Fig. XXXVI.— Knaurs. 



are sometimes collected into clusters (Pig. XXXVI. a), and may 

 exhibit little or no appearance of a tendency to further growth. 

 It is, however, not. imcommon to find them lengthening into 

 branches, as is shown in the Poplar (Fig. XXXVI. c), for which I 

 am indebted to Sir Oswald Mosley ; and although they have never 

 yet been used for the purposes of propagation, except in the 

 case of the Olive, there seems to be no reason why they should 

 not be so employed, if any necessity were to arise for them. 

 The real amount of their powers of growth is unknown, and 

 Would be a good subject of investigation. 



It will have been seen that the mode of propagation here 

 explained is analogous to that by seed, both having for their 



