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VARIETIES OF VARIATION.* 



The seed of a plant and the egg of an animal are 

 practically identical in their nature, and equally marvellous. 

 Each consists roughly of three items, a fertilised germ, 

 a store of nourishment, and a protective envelope. Each 

 is the result of a conjunction of potencies derived from two 

 dififerent sources, and each contains the two sets so com- 

 bined that, given congenial conditions, a new individual 

 will be developed resembling, as a general rule, the parental 

 form. We say as a general rule because there are excep- 

 tions, and these exceptions are of two diverse kinds. 



In the first case, the parents may be of dissimilar type 

 to each other, i.e. either different varieties of the same 

 species, or different species entirely. In this case, the 

 result of the combination may be an intermediate form of 

 individual showing more or less the peculiarities of both 

 parents, but resembling neither exactly ; or it may yield 

 one of the parental forms apparently unmodified, but which 

 will nevertheless show by its offspring that it contained 

 latent characters as well as patent ones, the other 

 parental form asserting itself again. The other kind of 

 exception is far more puzzling, since it is that which 

 embraces sudden " sports," in which quite new characters 

 not only appear, but are so fixed in the plant's system that 

 its offspring may reproduce the new type without any 

 reversion to the old one. With hybrids, or crosses, of the 

 former category the cultivator can usually form some idea 

 of what the result may be, and he can work to more or less 

 definite ends, but with the latter category he can exercise 

 no control at all. 



He may make a pure, i.e. unmixed, sowing of a hitherto 

 perfectly constant plant, and among the resulting brood 

 there may be a quite distinct form, indubitably of that 

 particular species, but departing from its special characters 



• By permission of the Gardeners' Magazine. 



