SUMMARY OR CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MICROSCOPY, Etc.* 
BOTANY. 
(Under the direction of A. B. Rendle, M.A., D.Sc., F.R.S., F.L.S.f 
GENERAL, 
Including the Anatomy and Physiology of Seed Plants. 
Cytology, 
Including- Cell-Contents. 
Behaviour of Homologous Chromosomes in Canna. — J. Belling 
( Proc . Nat. Acad. Sci., 1921, 7 , 197-201, 2 figs.). A study of the 
behaviour of homologous chromosomes in triploid varieties of Canna. 
Forty-six different species of Canna were grown, and most of these were 
diploid ; the pollen -mother-cells showed 9 dyads before the first division, 
and in the majority of the plants these separated into 9 + 9. One 
regularly triploid species differed from other Cannas with more than 18 
single chromosomes in being of smaller size, and in having smaller 
flowers. In 18 pollen-mother-cells the total number of chromosomes 
was 27 ; there were usually 9 triads, each of which divided into 2 and 
1 on the spindle, and travelled at random to the 2 poles. A similar 
arrangement, although less distinct, was found in a triploid Datura. 
S. GREVES. 
Counting Chromosomes in Pollen. — J. Belling (. Amer . Natur., 1921, 
55 , 578-4). A description of a new method of staining which has had 
very satisfactory results in the study of the different chromosome- 
numbers in certain mutants and hybrids. “To a quantity of aceto- 
carmine a trace of a solution of ferric hydrate dissolved in 45 p.c. acetic 
acid is added until the liquid becomes bluish-red, but no visible 
precipitate forms. An equal amount of ordinary aceto-carmine is then 
added. The anthers are teased out with nickel instruments. If the 
stain is too dark more aceto-carmine is to be supplied. It may be 
diluted with 45 p.c. acetic.” The chromosomes appear most distinctly 
in the metaphase of the second division, and the preparations will keep 
a week or more if an excess of stain and of iron are avoided. The 
cytoplasm remains unstained, while the chromosomes are a deep bluish- 
red. S. G. 
* The Society does not hold itself responsible for the views of the authors 
of the papers abstracted. The object of this part of the Journal is to present 
a summary of the papers as actually published, and to describe and illustrate 
Instruments, Apparatus, etc., which are either new or have not been previously 
described in this country. 
