574 Humphrey. — On some 
for the pollen- mother-cells of Lilium Martagon . The granules 
in and about Farmer’s spindles appear to be of a nucleolar 
nature. And if Strasburger’s present view that the role of the 
nucleolar substance is to form the spindle-fibres be correct, 
these apparently multipolar spindles may be unusual forms 
due to the presence of an excess of nucleolar substance in the 
cells concerned. At all events, as already suggested, a better 
knowledge of the relations of the amounts and proportions of 
the substances taken up by the plant, or of the influence of the 
conditions which further or retard growth, to the cell- con- 
stituents, may explain many such phenomena as those which 
are here in question. 
For fixing material to show the centrosomes, not all fluids 
are equally good. With favourable objects alcohol does well. 
But in general, and especially for vegetative tissues, where the 
cell-structure is less conspicuously developed, nothing has 
given me better results than Hermann’s platinum-chloride- 
osmic-acetic mixture. Subsequent staining by the long and 
tedious process recommended by this author for showing 
animal centrosomes, gives less satisfactory results than the 
simple fuchsin-iodine-green stain. As has been remarked, 
the former brings out various proteid granules in the cyto- 
plasm as conspicuously as the centrosomes ; with the latter 
stain the centrosomes come out distinctly and the other 
bodies remain uncoloured. The difference is shown in Figs. 
11 and 12 , from the root-tip of the Onion. Both are from 
material fixed with Hermann’s fluid ; but the section from 
which Fig. n is taken was stained on the slide by Zimmer- 
mann’s method, while Fig. 12 is from a root-tip stained in toto 
according to Hermann. The writer can therefore confirm the 
recent statements of Schaffner (’94), that centrospheres occur 
in their usual form in these young vegetative cells of the 
Onion root. But, as may be understood from Fig. 12, it is 
much easier to find bodies which one who is determined to 
find them may interpret as centrospheres, in sections stained 
by Hermann’s method, largely used by Schaffner, than in 
those treated in a better way. 
