126 ANDREWS. 



ents of the living substance ; or constant products of its activi- 

 ties ; or a necessary and invariable part of its most intimate 

 conditioning.^ And whatever may be the destiny of the mate- 

 rials introduced into, or formed by chemical activities within, the 

 living substance, their first, inescapable, function is assuredly 

 as pellicular or lamellar environment. 



Such physical and chemical conditions as are introduced into 

 protoplasm yield but heterogeneous stimuli — a most mixed 

 environment — for the substance. Since for organized activity, 

 organized specific environment, is needed and provided, the 

 bringing together, the chemical preparation, and the peculiar 

 grouping, of the various substances which serve in this capacity, 

 form the problem to be solved. 



[119] In non-living, or perfectly inert foams, there is a tend- 

 ency for vesicles of similar size and bearing similar contents 

 to become gradually grouped together, and for these latter 

 where fluid to coalesce. It is not such mechanical aggrega- 

 tions as these we must explain in protoplasm, but such aggre- 

 gations and such segregations as take place under conditions 

 seeming to contradict those demanded by the given physical 

 explanation. We must account often for a subdivision or 

 reduction in size of these kindred inclusions when brought 

 together, and for specific redistributions of the continuous sub- 

 stance : We must explain complex deportations of substances 

 from areas where physiological activities of a sort to which 

 these are physically an impediment appear later ; and, in other 

 areas, a rapid massing together of inclusions peculiarly favour- 

 able or necessary to the physiological functions called for there. 

 Most difficult of all, we must account for these physically 

 complex and highly organized phenomena taking place almost 

 instantaneously as response, not only to specific chemical or 

 physical environment of an accustomed sort, but to a wide 

 range of such stimuli, even those never before experienced, 

 and to very local stimuli, of a purely physical nature applied to 

 some distant area of the organism ; the physiological response 

 being often made in defiance of certain strong physical handi- 

 caps in environmental conditions. 



1 Finding none suitable, I am forced to create this noun for a term of my results. 



