1 64 ANDREWS. 



duced in situ, so that these, when poured out at intervals, can 

 by their quantity strongly influence other relatively large 

 areas, or similar organs on an equal vesicular scale. It repre- 

 sents naturally a certain decrease of osmotic compulsion, and 

 of lamellar tension and mass viscosity, and greater economy of 

 lamellar material with reservation of its stimulus. Its inclu- 

 sions both by the physical opportunity and compulsions they 

 offer, and by the chemical interactions they supply and create, 

 serve indubitably to maintain the local and general substance 

 in functional activity. Thus they come to mean reserves or 

 grosser conditionings on which life and habit of the race sub- 

 stance can depend. Such an alveolar structure alters and 

 influences functional rhythms. Possibilities of substance para- 

 sitism are much increased by it, and this is of radical impor- 

 tance. Such a structure means again, increase of mass with 

 many fruitful chemical and physical relations which can mater- 

 ially affect the fate of organisms. Above all, it offers oppor- 

 tunities for sudden irritable and contractile organization of 

 specific sorts ; and for sudden intensification of the powers of 

 the substance, as well as of swift recuperation and nutrition or 

 stimulation for this, since formation of a finely subdivided foam 

 from a structure of Biitschli, brings at once into play an im- 

 mense amount of reserve material and in such a manner as to 

 yield at a given moment stimulus and food to the largest area 

 of irritable substance. Basis for organized response as well as 

 nutrition and stimulus can thus be swiftly and enormously in- 

 creased within a given space limit. Since this change takes 

 place in the finer foam also, it is clear that even there, 

 resources over and above those for immediate function are 

 carried. I have already shown that formation and physical 

 modification of ectosarcal areas must have a powerful effect on 

 form, motions, and ingesting habit, besides exerting a radical 

 guidance of the general habits and instincts, of organisms. 

 Since a mere physical incident of local segregation of fluid- 

 bearing alveoli, offers the contractile, irritable, substance op- 

 portunity for organized function of various sorts, it seems the 

 physical form alone of protoplasm may have been a potent, 

 and even a cogent, factor in evolution of organisms along lines 



