The finest results are naturally given by organs that are easily teased out, _e.g._ flies' eggs, or the Malpighian canals of insects. The staining solution is to be chosen so that the act of staining does not last too long, but on the other hand too high a concentration must not be used. About 1/50000 to 1/100000 is recommended, so that the protoplasm and nucleus remain quite uncoloured. Artificial products with this method cannot entirely be excluded, and, _e.g._ in plant-cells containing tannin, are to be explained by the production and precipitation of the salt of tannic acid. However it is not difficult for the experienced to recognise artificial products as such in individual cases. The kind of granulation, the typical distribution, a comparison with neighbouring cells, the combination of various methods, the comparison of the same object under vital and "=survival=" staining, facilitate judgment and obviate mistakes of this kind. The majority of the granules of vertebrates are stained orange-red by neutral red, corresponding with the weakly alkaline reaction of these forms. Granules staining in pure fuchsin colour and which hence possess a weak acid reaction are much more rarely found. Combination staining may be recommended as a valuable aid to the neutral red method. Ehrlich has used a double stain with neutral red and methylene blue. Frog's larvae were allowed to remain in a solution of neutral red, to which a trace of methylene blue had been added. He then found red granulations almost exclusively, only the granules of the smooth musculature of the stomach were stained intensely blue. With the aid of a threefold combination Ehrlich obtained a still further differentiation of the living cell-granules. There is no doubt whatever that a thorough study of this neutral red method would lead to important conclusions as to the nature and function of the granules, and lead us to the most real problems of cell life. With our present information even we can get definite conceptions founded upon facts, as to the =biological importance of the cell-granules=. * * * * *