Vol. 2] Gardner. — Cytological Studies in Cyanophyceae. 269 



(6) THE GRANULES. 



The granular inclusions of the Cyanophyceae cell have occa- 

 sioned much controversy. The questions of dispute have related 

 to their number in a cell, their constancy, their location, their 

 chemical composition, their function, and the number of kinds. 



With the writer they have not been a subject of thorough in- 

 vestigation, yet some things have been quite definitely deter- 

 mined about them and these are recorded here. The investigation 

 has led to the discovery of but two kinds of granules in the Cya- 

 nophyceae cell. These are doubtless the same that have been seen 

 by many writers, but no attempt will be made here to try to har- 

 monize the writer's discoveries with those of other workers, for 

 it would probably only lead to further confusion of an already 

 tangled subject. A number of different names have been em- 

 ployed to designate these various kinds of granules, some relat- 

 ing to their location, some to their reaction to stains, and some to 

 their chemical composition and function. I am not at present 

 prepared to say what terms should be used to designate these two 

 sorts of structures which I have differentiated, and for conven- 

 ience in this paper will employ the terms a and /? for this pur- 

 pose. 



My conclusion that there are two kinds of granules present is 

 based mainly upon their behavior toward stains. No chemical 

 tests have been made. Results obtained by straining are at times 

 deceptive, and should be supplemented by other methods. In the 

 study of the granules the writer proceeded in a similar manner 

 as in the study of the nucleus, finding out as much as possible 

 with the living material, then by the application of concentrated 

 aqueous stains to the living material. About all one can discover 

 in the living material is that in certain species granules are pres- 

 ent and some of them are arranged in quite a definite way, e.g., 

 along the cross-walls. In other species granules may be seen in 

 the center of the cell, but in neither of these cases can one always 

 see them in these locations, and further, if a species has them 

 located in both positions, one is not able to say where the dividing 

 line is, since they look very much alike in the living cell. To seg- 

 regate them it was necessary to employ some stain that would 



