12 . ANDREWS. 



all sizes, all gradations existing between a structure of i /i and 

 the fine pellicular structure above described, while transmuta- 

 tions of one set into the other may be readily seen. 



On the other hand, there are many areas to be found 

 where the structure of Butschli is wonderfully perfect and 

 even. 



[8] In such areas, as in all others whose substance I have 

 been able to trace from earlier states, I find that Biitschli's 

 structure expresses a secondary and special organization of the 

 distribution of the elements of protoplasm, rather than a final, 

 or intrinsic, arrangement of these. 



Kindred organization of the elements is seen in the Protozoa 

 everywhere, heralding, and indeed making possible, areal spe- 

 cialization and areal organization of physiological function ; and 

 in the development of Metazoan embryos, the larval and em- 

 bryonic physiological areas, or organs, were seen to be laid 

 down in the same way.^ 



[9] To sum up : Biitschli's structure, that is, the vesiculation 

 of J^ to I jM, is the true structure of protoplasm in so far only 

 as it is a characteristic arrangement of the elements in the form 

 of a viscous, foam-like, emulsion. 



[10] The secondary finer structures of the meshwork sub- 

 stance, taken in connection with certain activities of this, to be 

 described further on, seem to place beyond dispute, that the 

 structure of >^ to i /a, is not, indeed, the final structure of the 

 living substance, but that it is part only of an infinitely graded 

 series of vesiculations of the protoplasmic foam; whose minute- 

 ness it would be rash to limit even to the finest pellicular net- 

 work visible ; and whose coarseness it would be still more 

 arbitrary to limit by one /a. 



These facts were established during research upon the follow- 

 ing organisms : Amoeba proteus, Amoeba radiosa ; Actinophrys 

 sol ; Actinosphaerium Eichornii ; Raphidiophrys, of several un- 

 identified species ; Monads of numerous sorts ; Choano-Flagel- 

 lates of several species ; Vorticellidae in several families, notably 

 Epistylis ; Myxomycete found in salt water, Myxomycete found 

 in fresh water ; Stentor ; Acinetans ; Coleps hirtus ; and many 



1 See Areal Differentiation, and Striation. 



