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EXPLANATION OF PLATES LIV AND LV. 
All figures were drawn with the aid of a Zeiss camera lucida. 
PLATE LIV. Mitosis in Vegetative Cells. 
(All the figures, except Figs. 1 and 22, were drawn to the same scale, using a Zeiss microscope, 
compensating ocular 12, and a 2 mm. homogeneous immersion objective, numerical aperture 1*30, 
magnification 2,040. Fig. 1 was drawn using the same objective but an 18 Zeiss compensating 
ocular, magnification 3,250. The same objective was also used for Fig. 22, but an 8 Zeiss compen- 
sating ocular, magnification 1,430. The images were all drawn at a plane even with the base of the 
microscope. The figures are reproduced from the drawings without any reduction.) 
Fig. 1. A resting cell. The reticulum in the nucleus is delicate and open. Chromatin knots 
lie on it. Two large nucleoli are in the nucleus. Several vacuoles lie in the cytoplasm. Cell highly 
magnified. 
Fig. 2. Elongated nucleus. Linin strands have thickened and their number increased. There 
is also an increase in the number and size of the chromatin bodies. 
Figs. 3, 4, .5, 6. The chromatin bodies are becoming distributed on the linin in the form of 
chromomeres. A spireme is being formed, and it is contracting about the nucleolus. 
Figs. 7, 8. The spireme moving away from the nucleolus. It is then very uneven in thickness. 
