THE INDIVIDUAL AND THE SPECIES 195 



In the case of ordinarily bred offspring from parents 

 of the same species a large deviation from the parental 

 characters might be a malformation, or the result of 

 some irregularity of development. An " atavistic ' 

 variation we may regard as the reappearance of some 

 character present in a more or less remote ancestor. 

 Thus dogfishes and skates are no doubt descended 

 from some elasmobranch fish which possessed an 

 anterior dorsal fin. This fin persists in the dog-fishes, 

 but has been lost in the skates and rays. Yet it may 

 appear in the latter fishes as an atavistic variation. 



In a variety (following de Vries' analysis) a char- 

 acter which disappears is not really lost : it is only 

 suppressed, and it still exists in a latent form. Some 

 flowers are coloured, for instance, but there may be 

 varieties in the species to which they belong in which 

 the flowers are colourless. It may not be quite correct, 

 in the physical sense, to say that the colour has been 

 lost, but we may put it in this way. These flowers 

 are then coloured and colourless varieties of the same 

 species. Colour or lack of colour is not, however, 

 fixed in the variety, for the individual plant bearing 

 colourless flowers also bears in its organisation the 

 potentiality of producing coloured flowers. The petals 

 of a flower may be smooth or covered with hairs, and 

 in the same stock both of these varieties may occur. 

 But we must not speak of the presence or absence of 

 hairs as constituting a difference of kind : the smooth- 

 petalled flowers might be regarded as containing the 

 epidermal rudiments of hairs. So also coloured and 

 colourless flowers may be regarded as containing the 

 same kinds of pigment, but these pigments are mixed 

 in different proportions. Such a view enables us to 

 look upon these contrasting characters in the same 

 way as we look upon fluctuating variations, that is, 



