402 Mr. H. Wager. [Oct. 9, 



Delafiold's hsematoxylin, Heidenhain's iron haematoxylin, methyl ene 

 blue, fuchsin, methyl green and fuchsin, methyl green and eosin and 

 picro-carmine. The specimens may be mounted whole either in balsam 

 or glycerine or may be first of all sectioned in the microtome, by 

 which certain details of structure can be shown up more clearly. 



The Living Cell. In the examination of the living cell under a high 

 power objective it is not difficult to observe that the cell contents are 

 differentiated into two parts, an outer peripheral layer in which the 

 colouring matter is placed, and an inner central part which is colour- 

 less. The structure of these two regions is difficult to make out, but 

 both may contain granules of varying sizes, and in some of the larger 

 forms a distinct vesiculate structure can be observed. The outer 

 coloured layer appears in many cases to encroach upon the central 

 portion, which is thereby rendered irregular in outline, but in no case 

 was a penetration of the coloured layer into the middle of the central 

 region observed ; in the younger cells near the ends of the filament 

 the central portion is nearly always more regular in outline than in 

 the older cells. 



Cytoplasm. In all forms which admit of a careful examination of 

 stained specimens under high powers the structure of the cytoplasm 

 appears to be vesiculate or reticulate, the meshes or alveoli being 

 regularly arranged and somewhat drawn out in the radial and 

 longitudinal directions, so as to give in transverse sections an ap- 

 pearance of trabeculae radiating from the central body to the periphery 

 of the cell (fig. 3). When granules are present these are found in or on 

 the threads, never, so far as I can see, in the meshes of the network. 

 In young vigorous cells the cytoplasm presents uniformly the structure 

 just described, but in old and degenerating cells a very considerable 

 amount of vacuolization is observable in which the central body often 

 becomes involved, so that in such cases no distinction between central 

 body and peripheral cytoplasm can be seen. These vacuolar spaces 

 often contain a slightly coloured sap, probably produced by the 

 breaking down of the colouring matters and their diffusion into the 

 cytoplasm. 



Colouring Matter. It has not been possible to obtain any evidence 

 of the existence of a differentiated chromatophore, such as obtains in 

 the higher Algae, either in fresh or stained specimens, and I am, 

 therefore, quite unable to support Fischer's statement that the central 

 body is surrounded by a cylindrical chromatophore. The colouring 

 matter appears to be contained in minute granules distributed through 

 the cytoplasm in such large numbers as to give the appearance of 

 a uniform diffuse coloration to the whole of the peripheral layer. 

 They appear in many cases to be arranged in regular rows which 

 run slightly obliquely across the cell, and are so clearly defined in 

 some forms as to give the impression that they are contained in definite 





