~ 
408 . BOTANICAL GAZETTE [DECEMBER 
the volume is entitled coordination, and contains chapters on Thallophytes 
and Schizophytes, Myxomycetes and fungi, algae, lichens, and a final chapter 
on immunity among plants. It is an elementary treatise, written in enter- 
taining and lucid style. That the author has been dead ten years accounts 
for the appearance of occasional remarks which do not quite reflect our latest 
knowledge, as for instance, that “the formula for the constitution of chlorophyll 
is not known.” Beginners, ela in botany or French, would find it a delight- 
ful little eine Cc. A. Suu 
MINOR NOTICES 
Flora of Natal.—Brws,3 well known for his ecological study of the vege- 
tation of Natal, has published a taxonomic account of the flora “‘for the purpose 
lytical keys are remarkably simple, leading to the genera, but the species are 
merely listed, with their ecological range and often with their local Zulu names. 
he author states that “the flowering plants of Natal, as now <i, 
belong to 148 families, and include go1 genera and 3786 species.””—J. M 
Osmotic pressure.—The publication of a new edition of Pfeffer’s4 famous 
work on osmotic pressure will be welcomed by students of plant physiology and 
physical chemistry who have desired to own a copy of this classic work. No 
changes have been made from the first edition, except that an introductory 
appreciation of PFEFFER’s work by Czapex precedes the text.—C. A. SHULL. 
NOTES FOR STUDENTS 
Specificity of chromosomes and sex-determination.—For a final proof of 
the réle of the individual chromosome we must look to the remarkable investi- 
gations of Bripces.’ It was this author who furnished a direct demonstra- 
tion of the chromosome theory of heredity, when he showed that irregular 
distributions of the sex chromosomes of Drosophila were accompanied by 
irregularities in the inheritance of known sex-linked factors. He now® pro- 
vides a similar demonstration of the specificity of the autosomes, and at the 
3 Bews, J. W., The flora of Natal and Zululand. pp. vi+248. Pietermaritzburg. 
pa 15s. (Whelden and Wesley, 28 Essex St., Strand, London 
PFEFFER, W., Osmotische Untersuchungen. pp. xiv-+236. figs. 5. Leipzig: 
reece 1921 
5 Bripces, C. 8B. Non-disjunction as proof of the chromosome theory of heredity. 
Genetics 1:1-52. 1916 
6 
192r. 
, Triploid intersexes in Drosophila melanogaster. Science 54:252-254. 
