CLASSIFICATION OF VARIATIONS 75 



always transmitted. They form — at least some of them form — 

 the raw material of organic evolution. 



§ 4. Classification and Illustration of Variations. 



" Yariation." — It is a common confession of naturalists 

 that a label is a necessary evil. A collection without labels is 

 a contradiction in terms, and yet the label is often a full-stop 

 to investigation. This is true in regard to the concrete ; it is 

 more lamentably true in regard to the abstract. Thus the 

 label " Variation " has been a great hindrance to progress. 



As Mr. Bateson says (1905, p. 575) : " The indiscriminate 

 confounding of all divergences from type into one heterogeneous 

 heap under the name ' Variation ' effectually concealed those 

 features of order which the phenomena severally present, 

 creating an enduring obstacle to the progress of evolutionary 

 science. Specific normality and distinctness being regarded 

 as an accidental product of exigency, it was thought safe to 

 treat departures from such normality as comparable differences : 

 all were ' variations ' alike." 



All organic changes imply some incompleteness in the heredi- 

 tary resemblance — a little more of one character, a little less of 

 another, or the occurrence of some feature which deserves to 

 be called distinctly " new." Both variations and modifications 

 may cause this incompleteness in the hereditary resemblance ; 

 an apparently similar condition may result from two different 

 processes of change. But the variation has a germinal origin, 

 is blastogenic, is not directly dependent on the external con- 

 ditions of life, is endogenous, and is transmissible ; while the 

 modification has a somatic origin, is the direct result of functional 

 or environmental influence, is exogenous, and, so far as we 

 know at present, is not as such transmissible. 



Classification. — There are many different ways of classifying 

 these variations which form the raw material of evolutionary 

 change. 



