1904] MERRIMAN: VEGETATIVE CELL DIVISION 207 
noted here in surface view, the tetrad structure in the end view; killed in 
Flemming’s weaker solution six hours; stained with Heidenhain’s bactiay 
toxylin with iron alum. 2440. 
Fic. 40. Longitudinal section of a periblem cell in the metaphase ; 
killed in chrom-acetic ; stained with Heidenhain’s haematoxylin and orange 
i. & 2440. 
Fig, 41. Longitudinal section of a periblem cell in the metaphase show- 
ing the disintegration of the chromosomes into tetrads; killed in chrom- 
acetic; stained with Delafield’s haematoxylin in combination with eosin, 
X 2440. 
Figs. 42-45. From a longitudinal section of a periblem cell, drawn in 
order of sectioning so as to admit of reconstruction; this stage was considered 
important as showing the disintegration into tetrads of the chromosomes, 
their fusion into spireme, the appearance of the linin interspireme bridges, 
and the substance which later resolves into the nucleoli; killed with chrom- 
acetic; stained with Heidenhain’s haematoxylin with iron alum. X 2440. 
F1G. 46. Longitudinal section of periblem cell showing the chromatin 
masses arranged in rings; killed in Flemming’s weaker solution; stained 
with Heidenhain’s haematoxylin with iron alum. X 2 
Figs. 47-48. Longitudinal sections of periblem al in the anaphase; 
the nucleoli have appeared as discrete bodies; the nuclear membranes are as 
yet unformed; killed in chrom-acetic; stained with Heidenhain’s haema- 
toxylin with iron alum in combination with orange G. 2440. 
IG. 49. Longitudinal section of periblem cells in the late anaphase; 
the double thread in the spireme is conspicuous in the reconstructing daughter 
nuclei; the cell wall is nearly completed; drawn with Leitz one-twelfth oil 
Seisiersion and Zeiss ocular 12. 
IGS. 50-51, Longitudinal sections of cells of plerome, the large central 
cellsand the elongating cells showing the structure of the chromatic network ; 
killed in Flemming’s weaker solution; stained with Heidenhain’s haema- 
toxylin with iron alum. 2440. 
Fics. 52-56. Longitudinal sections of the elongating cells of the plerome, 
Showing the peculiarities in structure and behavior of the chromosomes; 
killed in chrom-acetic; stained with Heidenhain’s haematoxylin with iron 
alum, 
