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1906] BRIEFER ARTICLES 69 
myself very often obtained when the fixation had been imperfect. It 
is, of course, easy in these plants to secure admirable preparations of the 
stages preceding and following on the maiotic divisions, but I am sure 
Mr. Moore will agree with me as to the great difficulty encountered in 
successfully fixing the cell contents at this critical period. Personally, 
I have not found chromacetic acid (the fixative used by him) very suc- 
cessful, but obtained far better results with Flemming’s solution and, 
if due precautions are taken, with acetic alcohol. The latter, in par- 
ticular, has yielded results of especial excellence, owing partly, no doubt, 
to the relative rapidity with which it traverses the somewhat impervious 
cell wall—J. B. Farmer, Royal College oj Science, London. 
REPLY. 
PROFESSOR FARMER acknowledges that in 1894 he believed in the 
simultaneous distribution of the chromosomes to the four spores in Pal- 
lavicinia decipiens. His description stands as the only account of a pro- 
cess without parallel in the plant kingdom, and he must have realized its 
exceptional nature. The account became all the more remarkable when 
Professor FARMER’S own studies on a number of liverworts, published in 
the following year, showed two successive mitoses in the spore mother- 
cells as in other groups of plants. He acknowledges now that he may 
have missed the binucleate stage. This is precisely what I believe he did, 
but since I have not investigated P. decipiens I cannot assert that he did 
so. Now he states that this simultaneous distribution is really not the _ 
essential matter at all. Apparently the essential matter to him is his 
observation that several liverworts conform to the normal sequence of 
nuclear division during sporogenesis. Yet these conclusions, bearing as 
they do on Pallavicinia decipiens, served to emphasize the peculiarities of 
that account, and I feel confident that most, if not all, cytologists would 
pick out the description of a simultaneous distribution of chromosomes as - 
the most essential feature of his paper of 1894. 
I venture to think that botanists are not so much interested in the 
explanations which Professor FARMER may make of what he did or did 
not believe in 1894 and 1895 relative to the quadripolar spindle (which 
opinions they can form for themselves), as in the facts of sporogenesis in 
the liverworts. My study of Pallavicinia Lyellii is plainly a challenge of 
his account of P. decipiens, and together with Professor Davis’s work on 
Pellia, leads us to believe that the ‘‘quadripolar spindle” in all liverworts is 
a phenomenon of prophase followed by spindles of two successive mitoses, 
in essential agreement with the events of sporogenesis in other plants. 
