No. 580] ORIGIN OF SINGLE CHARACTERS 220 



m a state of nature. The vast majority of observa- 

 tions on the evolution of mammals either in the field 

 (e. g., Osgood) or among fossil series, where the in- 

 ter gradations have not been destroyed, points to con- 

 tinuity in the origin of changes of proportion. The evi- 

 dence as to this continuity both in proportional and in cer- 

 tain numerical characters in fossil vertebrates and in- 

 vertebrates is overwhelming. Saltation is, however, theo- 

 retically probable in certain numerical and meristic char- 

 acters, such as supernumerary teeth and vertebra?. 



8. The Separability of Characters in the Body 

 Apart from the question of the origin of new charac- 

 ters by saltation, the observations of De Vries and his 

 followers furnish additional evidence of the separability 

 of characters both in the body and in the germ. This 

 law of separability in its human aspect was well ex- 

 pressed by G-alton in 1889. 20 



... We seem to inherit bit by bit, this element from one progenitor, that 

 from another, under conditions that will be more clearly expressed as we 

 proceed, while the several bits are themselves liable to some small change 

 during the process of transmission. Inheritance may therefore be described 

 as largely if not wholly "particulate," and as such it will be treated in 

 these pages. Though this word is good English and accurately expresses 

 its own meaning, the application now made of it will be better understood 

 through an illustration. Thus, many of the modern buildings in Italy are 

 historically known to have been built out of the pillaged structures of older 

 days. Here we may observe a column or a lintel serving the same purpose 

 for a second time, and perhaps bearing an inscription that testifies to its 

 origin, while as to the other stones, though the mason may have chipped 



direct from the quarry. This simile gives a rude though true idea of the 

 exact meaning of Particulate Inheritance, namely, that each piece of the 

 new structure is derived from a corresponding piece of some older one, as 



