His view is that certain well-known properties of organized bodies require for their explanation the admission that the simplest visible structure is itself made up of an arrangement of units of a far inferior order of minuteness. It is these hypothetical units that Nägeli has called Micellae.Now, Nägeli, in the first instance, confounded the micella with molecules, conceiving that the molecule of living matter must be of enormous size. But inasmuch as we have no reason for believing that any form of living material is chemically homogeneous, it was soon recognized, perhaps first by Pfeffer, but eventually also by Nägeli himself, that a micella, the ultimate element of living material, is not equivalent to a molecule, however big or complex, but must rather be an arrangement or phalanx of molecules of different kinds. Hence the word Tagma, first used by Pfeffer, has come to be accepted as best expressing the notion. And here it must be noted that each of the physiologists to whom reference has been made, regards the micella, not as a mere aggregate of separate particles, but as connected together so as to form a system...
1889 Prof. J. S. Burdon Sanderson: Elementary Problems in Physiology. In: Annual Report of the Board of Regents of the Smithsonian Institution, 1890.