170 APPLICATION OF PRINCIPLES. 



ditions very different from those to wliicli they are 

 Eubjectin their natural state, the seed often refuses to 

 ripen, or even to commence the formation of an 

 embryo. In such cases, the skill of gardeners must 

 aid the workings of nature, and art must effect that 

 which the failiug powers of a plant are unable to bring 

 about of themselves. 



Sterility is a common malady of cultivated plants ; 

 the finer varieties of fruit, and all double and highly 

 cultivated flowers, being more frequently barren than 

 fertile. This arises from several different causes. 



The most common cause of sterility is an unnatural 

 developement of some organ in the vicinity of the 

 seed, which attracts to itself the organisable matter 

 that would otherwise be applicable to the support of 

 the seed. Of this the Pear, the Pine-apple, and the 

 Plantain are illustrative instances. The more deli- 

 cate varieties of Pear, such as the Gansel's Bergamot 

 and the Chaumontelle, have rarely any seeds; of 

 Pine-apple, none, except the Enville now and then, 

 have seeds, and that variety, though a large one, is 

 of little value for its delicacy, and probably ap- 

 proaches nearly to the wild state of the plant ; of 

 Plantains, few, except the wild and ci-abbed sorts, are 

 seedful. The remedy for this appears to be, in with- 

 holding from such plants all the sources from which 

 their succulence can be encouraged. If, in conse- 

 quence of any predisposition to form succulent tissue 

 (on which the excellence of fruit much depends), the 

 organisable matter of the plant be once diverted from 

 feeding the seed to those parts in which the succu- 



