38 ANDREWS. 



To sum up all that has here been brought forward as to 

 pellicles. 



[32] Pellicles are of the interalveolar substance ; and we 

 shall presently see, that here, as elsewhere, the substance 

 preserves in toto its inherent powers; so that there are not 

 found in masses activities and characters, which are not 

 found also in pellicles and small areas of the interalveolar 

 stuff — areas so small that we cannot assign a limit to their 

 minuteness.^ 



Pellicles are, characterized by a hyaline, and, with all but the 

 highest powers, a structureless appearance. Their inclusions 

 are for the most part fluid ; if we exclude the so-called " gran- 

 ules," they are optically wholly so. 



(a) Pellicles, whether as passive masses of interalveolar 

 foam, or as contractile membranes, are organizations of the 

 two groups of elements of protoplasm, on a basis of its visco- 

 fluid foam character, 



(b) This organization is in direct correlation with physio- 

 logical activities of the substance ; and hence I hold pellicles 

 to be true substance organs. 



(c) They represent the necessary primitive type of physio- 

 logical organization of the substance ; and are therefore typical 

 of the primitive type of substance organ. 



(d) They epitomize also all typical substance organization 

 for reaction, in character, to environment. 



(e) They are the primitive, as they are still the characteristic, 

 end-organ of the living substance, as such. 



(f) They have, therefore, in this respect also, the character 

 of all true ectosarcal formation. 



(g) Pellicles are the primitive ectosarcal formation, and 

 are, in their origin as well as function, typical of all ectosarcal 

 formation. 



(h) Because of both their form and function it seems to 

 me impossible to deny to pellicles the value of membranes, of 

 living membranes. For the substance as such, they are mem- 

 branes par excellence. 



There is the more reason for this view since all those struc- 



1 See Activities, — also Substance as Such. 



