SEED. 133 



233. And in proportion as it is deprived of the sun's direct rays, that 

 quality will diminish. 



234. So that a fruit which, when exposed to the sun, is sweet, when 

 grown where no direct light will reach it will be acid ; as Hears, Cherries, &c. 



235. Hence acidity may be corrected by exposure to light ; and excess- 

 ive sweetness, or insipidity, by removal from light. 



236. It is the property of succulent fruits which are acid when wild, to 

 acquire sweetness when cultivated, losing part of their acid. 



237. This probably arises from the augmentation of the cellular tissue, 

 which possibly has a greater power than woody or vascular tissue of assist- 

 ing in the formation of sugar. 



23S. As a certain quantity of acid is essential to render fruit agreeable 

 to the palate, and as it is the property of cultivated fruits to add to their 

 saccharine matter, but not to form more acid than when wild ; it follows, 

 that in selecting wild fruits for domestication, those which are acid should 

 be preferred, and those which are sweet or insipid rejected 5 



239. Unless recourse is had to hybridism ; when a wild insipid fruit 

 may possibly be improved (204), or may be the means of improving 

 something else. 



240. It is very much upon such considerations as the foregoing that the 

 rules of training must depend. 



IX. Seed. 



241. The seed is the ovulum arrived at perfection. 



242. It consists of an integument enclosing an embryo, which is tho 

 rudiment of a future plant. 



243. The seed is nourished by the same means as the fruit ; and, like 

 it, will be more or less perfectly formed, according to the abundance of its 

 nutriment. 



244. The plant developed from the embryo in the seed, will be in all 

 essential particulars like its parent species, 



245. Unless its nature has been changed by hybridizing (204). 



246. But although it will certainly, under ordinary circumstances, repro- 

 duce its species, it will by no means uniformly reproduce the particular 

 variety by which it was borne. 



247. So that seed are not the proper means of propagating varieties. 



248. Nevertheless, in annual or biennial plants, no means can be em- 

 ployed for propagating a variety, except the seed 5 and yet the variety is 

 preserved. 



249. This is accomplished solely by the great care of the cultivator, and 

 happens thus : 



250. Although a seed will not absolutely propagate the individual, yet 

 as a seed will partake more of the nature of its actual parent than of any 

 thing else, its progeny may be expected, as really happens, to resemble the 

 variety from which it sprung, more than any other variety of its species ; 



251. Provided its purity has not been contaminated by the intermix- 

 ture of other varieties. 



252. By a careful eradication of all the varieties from the neighbourhood 

 of that from which seed is to be saved 5 by taking care that none but the 

 most genuine forms of a variety are preserved as seed-plants ; and by com- 



