376 BOTANICAL GAZETTE [DECEMBER 
nearly complete before the disappearance of the nucleolus. In his renewed 
observations on Osmunda, Strasburger has noted the large and varying num- 
ber (20-22) of chromatic groups in the spore mother cell. Each such group 
he regards as a chromosome pair. He finds the number of chromosomes 
in the prothallial cells is not so constantly twelve as he formerly (15) stated ; 
it may reach sixteen or more. It is therefore certain that the current view 
as to the constancy of chromosome numbers cannot be maintained, at least 
as regards Osmunda. 
MCMASTER UNIVERSITY, 
Toronto, Canada. 
LITERATURE CITED. 
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3. ———: Ueber Spermatogenese bei den Schactithalnee Ber. d. Deutsch. 
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dophytes. Bull. Torr, Bot. Club 24: 101-116, 1897. 
4. GUIGNARD, L.: Le développement du pollen et la réduction chromatique 
dans de Naias major. Arch. d’Anat. Microscopique 2: 455-599 
1899. 
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mother cells of Cobaca scandens. Proc. Cal. Acad. Sci. Bot. 
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: Origin of the cones of the multipolar spindle in Gladiolus. Bor. 
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ear ering der Kern und Zelltheilung. 
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4. 
8a, 
lung in ae 
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10b. 
