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JOHN BELLING. 



rings with a long V, the plane of the V being at right angles to 

 that of the adjacent ring. At the metaphase, as shown in Fig. 2 

 of the present paper, one large ring and V may be present. The 



FIG. 2. First metaphase (to anaphase) in a pollen-mother-cell, from a plant 

 forced in the greenhouse, in March, 1923. This cell was selected as showing no 

 overlapping bivalents. In bivalents I., II. and III., the spindle fibers would 

 probably be attached where the constituent chromosomes seem to cross. 



division into chromatids cannot be seen in face view, but only 

 when the rings or V's are presented edgeways. In the next 

 stage, which is not figured here, a small loop arises from the 



FIG. 3. First metaphase to anaphase in a pollen-mother-cell. Drawn in 

 March, 1924; after a spell of cold weather. The drawing surface was shifted after 

 outlining each bivalent, as was done also in Figs. 4 and 5. Bivalent VI. has the 

 more or less exceptional configuration noted in the text in bivalent IV. Bivalent 

 VII. is the most advanced in separation. 



