100 THE DATA OF BIOLOGY. 



be regarded as progressive or continuous adjustments of in- 

 ternal relations to external relations. So that not only does 

 the definition, as thus expressed, comprehend all those activi- 

 ties, bodily and mental, which constitute our ordinary idea of 

 Life; but it also comprehends both those processes of de- 

 velopment by which the organism is brought into general fit- 

 ness for such activities, and those after-processes of adapta- 

 tion by which it is specially fitted to its special activities. 



Nevertheless, so abstract a formula as this is scarcely 

 fitted for our present purpose. Eeserving it for use where 

 specially appropriate, it will be best commonly to employ its 

 more concrete equivalent — to consider the internal relations 

 as " definite combinations of simultaneous and successive 

 changes ; " the external relations as " co-existences and se- 

 quences ; ^' and the connexion between them as a " corre- 

 spondence." 



