80 THE DATA. OF BIOLOGY. 



altered relation in the surrounding medium between tho 

 quantity of heat absorbed from, and radiated to, bodies of a 

 given temperature, is counterbalanced. If a sound or a scent 

 wafted to it on the breeze, prompts the stag to dart away 

 from the deer-stalker ; it is that there exists in its neighbour- 

 hood a relation between a certain sensible property and cer- 

 tain actions dangerous to the stag, while in its organism 

 there exists an adapted relation between the impression this 

 sensible property produces, and the actions by which danger 

 is escaped. If inquiry has led the chemist to a law, enabling 

 him to tell how much of any one element will combine with 

 so much of another ; it is that there has been established 

 in him specific mental relations, which accord with specific 

 chemical relations in the things around. Seeing, then, that in 

 all cases we may consider the external phenomena as simply 

 in relation, and the internal phenomena also as simply in re- 

 lation ; the broadest and most complete definition of Life will 

 be — The continuous adjustment of internal relations to external 

 relations* 



While it is simpler, this modified formula has the further 

 advantage of being somewhat more comprehensive. To say 

 that it includes not only those definite combinations of simul- 

 taneous and successive changes in an organism, which cor- 

 respond to co-existences and sequences in the environment, 

 but also those structural arrangements which enable the or- 

 ganism to adapt its actions to actions in the environment, 

 may perhaps be going too far ; for though these structural 

 arrangements present internal relations adjusted to external 

 relations, yet the continuous adjustment of relations can 

 scarcely be held to include a fixed adjustment already made. 

 Clearly, Life, which is made up of dynamical phenomena, 

 cannot be defined in terms that shall at the same time define 

 the apparatus manifesting it, which presents only statical 

 phenomena. But while this antithesis serves to remind us 

 that the fundamental distinction between the organism and 



*' In further elucidation of this general doctrine, see First Principles, \ 25. 



