3.56 PRINCIPLES OF CLASSIFICATION. 



site course in domesticated plants, that is, by constantly insuring the 

 fertilization of the ovules of a marked variety by the pollen of the 

 same, and by saving seed only from such of the resulting progeny as 

 possess the desired peculiarity in the highest degree, and so on for 

 several generations, it would appear that 



G93. Races, viz. varieties whose characteristics are transmissible 

 by seed with considerable certainty, may generally be produced. Of 

 this kind are the particular sorts of Indian Corn, Rye, Cabbage, 

 Lettuce, Radishes, &c, and indeed of nearly all our varieties of culti- 

 vated annual and biennial esculent plants, as Avell as of several per- 

 ennials, many of which have been fixed through centuries of domes- 

 tication. What is now taking place with the Peach in this country 

 may convince us that races may be developed in trees as well as in 

 herbs, and in the same manner ; and that the reason why most of 

 our cultivated races are annuals or biennials is because these can 

 be perpetuated in no other way, and because the desired result 

 is obtainable in fewer years than in shrubs or trees. Although 

 races hardly exist independently of man, he cannot be said to origi- 

 nate their peculiarities, nor is it known how they originate. The 

 sports, as the gardener calls them, appear as it were accidentally 

 in cultivated plants. The cultivator merely selects the most promis- 

 ing sorts for preservation, leaving the others to their fate. By par- 

 ticular care he develops the characteristic feature, and strengthens 

 and fixes, in the manner already explained, the tendency to become 

 hereditary, so securing the transmissibility of the variety as long as 

 he takes sufficient care of it. If not duly cared for, they dwindle and 

 lose their peculiarities, or else perish ; if allowed to mix with normal 

 forms, they revert to the common state of the species. Were culti- 

 vation to cease, all these valued products of man's care and skill 

 Avould doubtless speedily disappear ; the greater part, perhaps, would 

 perish outright ; the remainder would revert, in a few generations 

 of spontaneous growth, to the character of the primitive stock. 



G94. Although man has no power to create the peculiarities of 

 such varieties, he may manage ?o as not only largely to increase 

 them, but also to combine the peculiarities of widely different varie- 

 ties of a species, and thereby produce novel results. This is effected 

 by Cross-breeding, i. e. by fertilizing the pistil of one variety with the 

 pollen of another variety of the same species. In this way most 

 esteemed new varieties of flowers and fruits are originated, which 

 combine the separate excellences of both parents. The cultivator 



