DARLING: MIrTosIs IN LIVING CELLS 409 
pollen mother cells in stages of division, although the presence 
of numerous starch grains and of granules in the cytoplasm often 
obscures the definiteness of the figures. 
Because of the simplicity of the means any one interested in 
seeing the chromosomes, nucleoli, and stages in the division of the 
living cell may do so with an ordinary compound microscope with 
a 1/6in. objective. The only difficulties that may arise are: to 
obtain the flower buds before division of the pollen mother cells 
has taken place, which may be four weeks or more before the 
flowers open, as was the case in the maples this year; the other 
difficulty may be in the density of the cytoplasm, but this varies 
with different species and with different anthers of the same species. 
These few observations are recorded to emphasize the fact 
that many of the phenomena presented in fixed and stained mate- 
rial can easily be verified as existing in the living cell. 
CoLuMBIA UNIVERSITY. 
