128 ANDREWS. 



presently no longer follow it, extending and repeating the 

 selection until all the protoplasm has chosen for itself, or 

 passed by, or rejected, for itself, and secured, so far as the 

 opportunities allowed, those special environmental conditions 

 by which its general and its specific activities may be main- 

 tained. 



Later, when all the ingested matter has been passed upon 

 thus, the substance as organism finally rejects and casts out 

 all the leavings of the substance as such, together with such 

 waste materials as have been thrown off by this during func- 

 tion. In addition to direct methods of ejection, there are 

 many indirect methods and also many special substance de- 

 vices for getting rid by more roundabout ways of deleterious, 

 or cumbersome, or inutile, matter. Area after area of organ- 

 ized physiological difference may be incited by presence of 

 ingested food, to produce such secretions as will aid in pre- 

 paring it for that diffusible state in which it can reach and 

 be used as opportunities by the ultimate lamellar subdivisions 

 of continuous substance in all parts of the organism. These 

 areas are indirectly incited, not by actual contact with the food, 

 and they act through their own existing conditions to aid in 

 preparing what may later furnish renewal of their own powers. 



[122] Actively by means of its physiological powers, and 

 passively by its chemical and physical nature and properties, 

 the substance secures a double series of judgments on its 

 internal environment. Then by new combinations and devices 

 of areal differentiation, always on the basis of the foam struc- 

 ture, it constantly extends its power of dealing as living sub- 

 stance with the heterogeneous opportunities of environment. 



[123] To restate; in securing its own environment, the 

 substance, both as such and as organism, exercises among 

 the sum of opportunities offered it by external environment 

 — a choice ; and in this choice manifests its own character. 

 The words " choice " and " selection " need carry no implica- 

 tion of conscious action on the part of the selecting substance. 

 They may be understood without further weight than is given 

 the selection by a magnet of some steel filings from amongst 

 glass and sawdust particles ; or a choice by the steel filings of 



