3o6 CULTIVATED PLANTS AND THEIR ORIGIN 



seedlings of these or any other species are exactly alike in all 

 respects. The variation may be merely morphological, that is, 

 it may consist in an alteration in the form and size of the leaf, 

 stem, or other part of the plant : the individuals may also differ 

 physiologically from their parents and from each other; for 

 example, among potatoes the seedlings differ in their power of 

 starch formation and storage, and in their capabihty of resisting 

 frost and the attacks of insects and parasitic fungi. 



The differences between the parents and their offspring in the 

 case of wild plants are usually very slight, but among a number 

 of cultivated plants the amount of variation seen in the seedling 

 is often very considerable. 



A seedling which differs very appreciably from its parent in 

 some of its morphological or physiological characteristics may be 

 termed a ' seminal sfort! 



Although many ' seminal sports ' , differ considerably from 

 the parent stock from which they have been obtained, it does 

 not follow that these varieties are necessarily improvements upon 

 the parents ; the majority are often mere curiosities, or distinctly 

 inferior varieties, with no intrinsic value from the farmer's or 

 gardener's point of view; others, however, frequently possess 

 characters of sufficient novelty and distinctness to render them 

 especially worthy of cultivation. 



The latter is perhaps most commonly the case among orna- 

 mental flowering plants, where each new variation in the colour 

 of the leaves or flowers is often sufficient to make the plant 

 attractive. 



Careful investigation into the origin of the many varieties of 

 apples, pears, and other fruits leads to the conclusion that by far 

 the larger number of them are ' seminal sports ' produced from 

 seeds casually sown in woods, hedgerows, and fields by birds or 

 self-sown in gardens : long ago they attracted the attention of 

 some one who considered the varieties worthy of cultivation. 



Several of the more modern varieties of fruits have arisen as 



