ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
65 
BOTANY. 
(Under the direction of A. B. Rendle, M.A., D.Sc., F.R.S., F.L.S.) 
GENERAL, 
Including the Anatomy and Physiology of Seed Plants. 
Cytoiogy, 
Including - Cell-Contents. 
Cytological Study of a few Composite. — Masato Tahara 
(Journ. Coll. Sc. Tokyo, 1921, 43, 1-53, 4 pis., 13 figs.). An account 
of the cytology of species of Chrysanthemum and Erigeron. Although 
many species of Chrysanthemum exhibit 18 or 9 chromosomes during 
cell-division (and these numbers are regarded as being characteristic of 
the genus) , several species show a variation in the number of haploid 
Fig. 2. 
Figs. 1-5. — Reduction- Division in Pollen-Mother- Cell of 
Chrysanthemum coronarium.. 
Fig. 1, Formation of parallel threads ; Fig. 2, Synapsis 
stage ; Fig. 3, Spireme stage ; Fig. 4, Contraction stage ; 
Fig. 5, Early diakinesis. 
chromosomes : thus C. indicum and C. Leucanthemum have 18, 
C. hakusanense and C. morifolium 21, C. Decaisneanum 36, and 
C. marginatum and C. arcticum 45. 
In a few species the seeds have numerous embryo-sac-mother-cells, 
but the reduction-division is normal. C. coronarium was found most 
suitable for the study of reduction-division of the pollen -mother-cells. 
The threads are parallel during early prophase ; the true longitudinal 
F 
