20 ANDREWS. 



viscidity. That the filose formations were fj'ee is not, on the 

 other hand, at all less likely, as will appear under Protoplasmic 

 Activities. The phenomena were seen to take place while the 

 general cuticle, as well as the whole mass of the animal, was 

 quite strongly contracted. 



[15] This proved that under the mask of a stable and even a 

 contracted area of Butschli's structure, local relaxations may 

 exist, rendering possible not only transfer of substance but 

 modification of the finer structure of the living substance. It 

 also went to show that of the two groups of elements it is not 

 the alveolar contents which play the leading role.^ 



Variations of size of alveoli in correlation with physiological 

 function will be discussed further on.^ 



[16] There are found in the living substance innumerable 

 contradictions of the conditions ruling the artificial foams of 

 Biitschli. Many of these are to be cited. It may be stated 

 here that as to size and distribution of inclusions, as in most 

 other particulars, while there are always cases to be met with 

 which coincide with the inorganic foams, there are more which 

 cannot be made to agree. 



An adequate explanation of living phenomena must meet all 

 the facts. 



Such intermingling of various matters as exists in protoplasm 

 must render chemical analysis of this, as living substance, forever 

 difficult, for besides the fact that the two sets of elements are 

 so finely subdivided and so intermixed in very small portions, — 

 portions so small indeed as to pass at times beyond microscopical 

 vision,^ — how shall it be determined which part of the result 

 belongs to which group .■* In our efforts to learn something 

 of the actual living substance, how shall we know which part 

 of a given reaction, or which among all the detected qualities 

 or matter, belong indeed to the living element ; which to the 

 intermingled and non-living matter } How may we know, which 

 part of local or temporary variations are due to local variations in 

 these latter; which to physiological difference in the functioning 



^ See Activities — filose. Also Striation. 

 2 See A real Differentiation — Ectosarc. 

 ^ See Living Substance as Such. 



