CORKESPONDENCE BETWEEN LIFE AND ITS CIRCUMSTANCES. 81 



its actions, is as wide as that between Matter and Motion, it 

 at the same time draws attention to the fact, that if the 

 structural arrangements of the adult are not properly in- 

 cluded in the definition, yet the developmental processes by 

 which those arrangements were established, are included. 

 For that process of evolution during which the organs of the 

 embryo are fitted to their prospective functions, is from be- 

 ginning to end the gradual or continuous adjustment of in- 

 ternal relations to external relations. Moreover, those struc- 

 tural modifications of the adult organism, which, under change 

 of climate, change of occupation, change of food, slowly bring 

 about some re-arrangement in the organic balance, must simi- 

 larly be regarded as continuous adjustments of internal re- 

 lations to external relations. So that not only does the de- 

 finition, as thus expressed, comprehend all those activities, 

 bodily and mental, which constitute our ordinary idea of Life ; 

 but it also comprehends, both those processes of development 

 by which the organism is brought into general fitness for 

 these activities, and those after-processes of adaptation by 

 which it is specially fitted to its special activities. 



Nevertheless, superior as it is in simplicity and comprehen- 

 siveness, so abstract a formula as this is scarcely fitted for 

 our present purpose. Reserving its terms for such use as oc- 

 casion may dictate, 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." 



