184 SOWING. 



the common oak, we can see considerable diversity of 

 habit and individual character. Some are conical 

 and aspiring ; others are stag-headed and spreading. 

 Such characters are conveyed by their seeds : hence 

 it becomes the duty of the nurseryman, and the inter- 

 est of every planter, to be careful in the selection of 

 seed, whether intended for sale or sowing. There are 

 certainly, for instance, two very distinct kinds of 

 Scotch pine, one, of course, being a variety. The 

 most common is of an upright and formal outline 

 when young, and having a thick suberous persisting 

 bark ; the second has a smoother bark in consequence 

 of the outer layers being thrown off piecemeal during 

 the growth ; it is also more irregular in form, and 

 often presents an outline highly picturesque. One 

 drawback against this last sort is, its liability to be 

 shattered by the weight of snow lodging on the 

 extended horizontal branches. The seeds of both 

 sorts are gathered together, and it is not till the 

 plants, raised from the mixture, are twenty years old, 

 that their peculiar characters appear. So of the oak, 

 Quercus rbbur, there are two varieties ( Q. sessiliflbra, 

 and Q. pedunculate*,} in our woods ; the seeds of both 

 are too often mixed and raised together, although the 

 last is said to be a superior tree, producing the most 

 valuable timber. 



These circumstances are mentioned to show the 

 necessity of pure seed being chosen from the best 

 specimens of the desired sorts, for the reasons above 

 given. 



It may be imagined, perhaps, that as a seed con- 



