INDIVIDUALS, SPECIES, AND VARIETIES. 351 



668. Varieties, This fraternal resemblance, or specific identity, 

 however, is not incompatible with individual peculiarity. If two 

 seeds from the same pod are sown in different soils, and submitted 

 to different conditions as respects heat, light, and moisture, the 

 plants that spring from them will show marks of this different 

 treatment in their appearance. Such differences are continually 

 arising in the natural course of things. To produce and increase, 

 and by artificial management to perpetuate, differences of this sort, 

 forms an important part of the art of cultivation. These minor de- 

 viations, not incompatible with the idea of a common origin, con- 

 stitute VARIETIES. Whenever the conditions that give rise to vari- 

 eties are carried to excess, these individuals fail to fructify, or 

 perish. When the conditions vary less widely from those most 

 propitious to the constitution of the particular species, a few years 

 or a few generations may suffice to bring the variety back to the 

 original form. In either case, the variation is transient. It must 

 either return to the common character of the species, or perish. 

 A certain flexibility is allowable ; but accidental and individual 

 variations tend to disappear with the causes which originate them, 

 or are destroyed by the continued operation of those causes. 



669. To this there is one class of exceptions, which is exceed- 

 ingly common in domesticated plants ; where the habit, once es- 

 tablished, outlasts the cause, and continues throughout the life of 

 the individual. The new buds and branches partake of the pecu- 

 liarity, and the variety may consequently be perpetuated by cut- 

 tings, grafts, &c. ; as is the case with our Apples, Pears, &c. But 

 this tendency does not inhere in the seed. 



670. Races, There is still another and more strongly marked 

 kind of variety, though unknown, perhaps, in a perfectly wild 

 state, in which the characteristics are transmissible by seed. 

 Particular varieties of Peas, Radishes, Lettuce, &c., are thus per- 

 petuated in our gardens ; and in agriculture, various sorts of grain 

 have thus been preserved from time immemorial. They have re- 

 ceived the name of Races. It is not known how they originate. 

 They start up, as it were, accidentally, from time to time, in culti- 

 vated plants. The cultivator selects the most promising sorts, or 

 " sports," for preservation, leaving the others to their fate. By 

 peculiar care he developes and strengthens the tendency to become 

 hereditary, and renders it paramount (under the circumstances and 

 conditions of cultivation) to that stronger natural tendency to re- 



