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this solution gradually change into almost pure turpentine, after which algae can safely be imbedded in 
Canada-balsam in turpentine (not too much concentrated) with no contraction at all. Thus I have obtained 
beautiful specimens of Zygnema, in which only pyrenoids, nuclei, and nucleoli are stained and other parts are 
almost colourless. 
The specific name of Zygnema in question could not be determined. For its structure I refer the 
readers to the middle cell (on the left side and not concerned in conjugation) in Lig. 4 a. 
The first step of the conjugation is the formation of two processes, one from each cell (ig. 1), which 
then meet and fuse with each other (Jig. 2). Then follows the disappearance of the common wall which 
separates the two processes (fig. 3), Up to this stage we see no change at all in both nuclei. The next 
stage is represented by the upper pair of cells in Lg. 4, where the nuclei of the two cells are already 
concerned in the process of fusion. At this stage, it seems as if both nuclei are connected by a very fine 
thread (⑰, but this so-called “thread” part seems to be nothing more than a part of the nuclei specially 
thinned during the conjugation. J was not fortunate enough to be able to follow the development of this 
thread,” but its formation is not difficult to be comprehended and proceeds probably as follows : Kach nucleus 
produces a thin process tapering inwards and these two procvsses meet to form the “thread.” This view is 
made highly probable by the fact that each nucleus tapers inwards very gradually and the “thread ” is therefore 
finest at its middle part, which indicates the meeting point of the two processes of nuclei. In the next 

On the Behaviour of the Nuclei during the Conjugation of Zyguema. 


