Inclusions in the protoplast 



13 



with methylene blue or with an aqueous solution of Bismarck brown, and 

 very deeply with haematoxylin. They are identical with the ' a granules ' of 

 Gardner ('06) and appear to be equivalent to A. Mayer's red granules 

 of volutin. They are of an albuminous nature and are insoluble in hydro- 

 chloric, nitric, or sulphuric acid; they are digested in about twenty-four 

 hours with artificial gastric juice. They give a phosphorus reaction and 

 contain masked iron. They are larger and more conspicuous than the 

 nucleo-protein granules (presumed chromatin granules) in the threads of 

 the mesh work of the primitive nucleus, and it is not unlikely that they also 

 consist largely of some nucleo-protein. 



Fischer ('05) has described the occurrence of what he terms 'anabaenin' in the 'central 

 body ' of various filamentous forms of the Myxophyceae. This substance he apparently 



Fig. 9. A, Chroococcus sp. [? Ghr. minutus (Kiitz.) Nag.] stained with brilliant blue to show the 

 cyanophycin granules, x 1200 (after a drawing by Miss Acton). B, Oscillatoria limosaA.g. t 

 end of a filament showing prominent cyanophycin granules on each side of the transverse 

 walls, x 800. 



identified with the central granules of certain other authors, but the identification is 

 exceedingly doubtful as he states that anabsenin is a carbohydrate and probably a trans- 

 formation product of glycogen. Fischer's observations with regard to anabsenin can 

 scarcely be reconciled with the published statements of other investigators of the 

 Blue-green Algae. It is possible that anabsonin is identical with the substance contained 

 in the mucus-vacuoles, as that substance is of a carbohydrate nature and the vacuoles 

 are often aggregated around the central body. 



(2) Cyanophycin granules. These granules were so named by Borzi 

 ('86), who considered them as a food reserve. They are identical with 

 the ' reserve granules ' of Btitschli and of Nadson, and with the ' ft granules ' 

 of Gardner. They occur only in the cytoplasmic zone, more especially in its 

 outer portion near the cell-wall, and in the Oscillatoriacese they are often 

 very conspicuous on each side of the transverse walls of the filament (fig. 9, 



