76 FUNDAMENTALS OF SUBMI C RO S COP I C MORPHOLOGY I 



developed for corpuscular dispersoids, is very small (blood, mil k, 

 serum, suspensions of micro-organisms and viruses). No conclusive 

 information could be derived by these methods on the fine structur e 

 of the protoplasm. The very terminology of the theory of dispersoid s, 

 which assumes dispersed particles in a dispersing medium, is unsuitable. 

 True, the introduction of dijJorM, i.e., strongly anisodiametric par- 

 ticles, accounts to a certain extent for the properties known to modern 

 macromolecular chemistry (Manegold, 1941). The older technical 

 terms of Nageli (Nageli and Schwendener, 1877) are much better 

 adapted to the needs of biologists working with gels. Nageli's 

 ideas can be applied to our present concept of gel structure. To that 

 end let us first give a precise definition of the micellar concept, to which 

 unfortunately various meanings have been attached in colloid science. 



d. Micellar Theory 



The concept of the micelle. C. Nageli was the first to develop a well-founded 

 theory on the structure of hydrogels, which he designated as organi-:^ed 

 substances. Starting from double refraction, anisotropy of swelling and layer 

 structure of grains of starch (18 5 8, new edition 1928) and of cell membranes, 

 he made the assumption that these substances consist of long, submicro- 

 scopic particles, supermolecular in character and of crystalline structure. Such 

 a particle was called a micelle (diminutive of the latin mica = a crumb or 

 little bit). 



Later, Nageli extended his theory to solutions. He stated that, when a 

 gel is dissolved, the micelles are maintained as units and give a micellar 

 solution. As a result of this transference of the micellar concept from solid 

 gels to solutions, this concept is used in the literature in various meanings, 

 as has been pointed out by several authors: Zsigmondy (1921), Ambronn 

 and Frey (1926, p. 152). Whereas the biologists, in particular Ambronn's 

 school (Frey, 1926a, 1928a, b) and also Schmidt (1934), adhere to the 

 original definition which indicates the: form and crystallinity of the particles, 

 the meaning attached to micelles by colloid chemists is as a rule simply 

 that of dispersed particles in a colloid solution, stressing in particular 

 their electrical charge, without heeding their form and structure. In the latter 

 case, therefore, it represents an overall concept which may embrace all 

 possibilities such as primary particles (monones), secondary particles 

 (polyones), associate^ (^-g-. i^^ soaps), etc., including their charges and 

 solvation layers. As a result of this situation, the origin of this term is 

 scarcely known in colloid chemistry. This led to what Nageli objected to in 

 a discussion of Pfeffer's terminology in the famous "Osmotische Unter- 

 suchungen" (1877). Nageli says (new edit. 1928, p. 70/71): "Pfeffer uses 

 the general expression 'tagma' for molecular compound, observing that in 

 chemistry one would hesitate to introduce the term micelle, which is re- 



