DISEASES OF INFANCY. 389 



a single year in the seed-beds, while others, either 

 because they never were affected by disease, or had 

 sufficient strength to pass through those exposures 

 which a plant, like a child, is peculiarly subject to 

 in a state of infancy, survive. It seems evident that 

 varieties die in obedience to some great law, higher 

 than that of disease, which accomplishes the work. 



" When, towards the end of the last century, Van 

 Mons commenced his essays, and published the 

 grounds of his theory upon the production of fruit 

 trees by means of successive generations, pomology 

 was entirely delivered from infancy and the dull 

 routine which she had long followed, and took her 

 position with the other sciences through the succes- 

 sive labors of Quintinie, Merlet, Legendre, and 

 Duhamel. The culture, the form, and the descrip- 

 tion of fruit trees were from that time established. 

 One point was not even alluded to in the works 

 of these latter authors ; this was that of the degen- 

 eracy or deterioration of varieties. 



" According to Van Mons, the cause of this degen- 

 eracy is the age of the variety. He thus expressed 

 himself: 



" ' The decay of the old varieties of fruit is gen- 

 erally complained of, and with reason. Every one 

 remarks the imperfections of the old sorts, and 

 avows it with grief. I know nothing so deplorable, 

 in point of culture, as to raise a tree in the hope of 

 deriving pleasure from its fruit, and to see it go to 

 33* 



