140 THE EVOLUTION OF CONTINUITY 



action of the modifying force mentioned ; and the appear- 

 ance of this variation may be called sudden. Yet it is but 

 the original two-cell variation evolved through Individual 

 development. As we shall see, for a modifying force to 

 produce its best results, as expressed by variation, it must 

 act early on the growth-cycle. It is really a recognition of 

 this truth which makes the responsible parent pay attention 

 to the upbringing of his child ; and here, as with our illus- 

 trative example, if good results are to be expected, the 

 modifying force must not only act early, but continue to 

 act during further development. 



The ruling Spirit of the universe acts through Environ- 

 ment (the term being used in the widest sense), and it may 

 thus be said that it is Environmental influence which guides 

 Evolution in all its aspects ; acquired variations being the 

 result of the action of some form of environmental force. 

 The force acts in innumerable forms, and in its relation to 

 a given object comes from all sources outside of this object. 

 Thus, for example, a man's Environment may be said to 

 be the rest of the Universe, or of the Whole of which he is 

 a part. The modifying forces which act on his development 

 may come as aether waves, as atmospheric pressure, as heat 

 or cold, or through dampness or moisture, food, parental 

 care, companionship, and in endless forms ; the child's 

 development may be affected by the geographical position 

 of his home, by the habits of his mother, by the shape of 

 his boots. Naturally, one distinguishes between immediate 

 and remote environment in connection with the acquisition 

 of variations, for it is directly acting influences which in the 

 end are the modifying factors. 



It may be remarked that some writers, while admitting 

 the action of Environment in producing a given acquired 

 variation, tend to limit its powers by attributing to the 

 object affected a purposive adaptation to the altered con- 

 ditions. For our own part we would agree to such purposive 

 adaptation if it be attributed to all living organisms, for 

 every living thing in Nature has the power to respond to 

 external influence, and in an unscientific sense responds 

 " purposively." For we hold that any acquired variation 

 whatsoever must of necessity be adaptive ; it represents 

 an effect produced in response to, and therefore in harmony 



