In examining starch-grains Nägeli came to the conclusion that molecules of different chemical character are grouped together at every visible point; the material which colours blue with iodine, the granulose, could be removed from the grains, and then there remained behind a skeleton of the starch-grain very poor in substance, but showing exactly the original stratification and giving no blue colour with iodine; this Nägeli named starch-cellulose. It followed from this behaviour, that two chemically different molecules lie everywhere side by side in the grain of starch, much as if red and yellow bricks had been so employed to build a house, that when all the yellow bricks were afterwards removed, the red alone would still represent the wall in its original form as a whole though in a looser condition. He arrived at similar results in the case of the crystalloid proteid bodies, which Theodor Hartig discovered, and Radlkofer had examined crystallographically, Maschke chemically. Since it is possible in the same manner to extract the so-called incrusting matters from cell-membranes without essentially altering their form, and to obtain ash-skeletons of them which imitate all the delicacies of their structure, the comparison adopted above may also be applied in still more complex manner to the molecular structure of these membranes; and indeed many considerations lead to the belief, that the ideas which Nägeli obtained from starch-grains may be applied with some modifications to the structure of protoplasm also.