RECENT PHYSIOLOGY 169 
corms, rhizomes, cuttings of leaves and stems, seeds, and spores. 
The later work was carried on in a specially built. dark bea 
entrance to which was gained by double doors, so arranged that no 
daylight was admitted; the plants were examined by aid of the 
light of a candle or a small electric hand-la amp. 
In pages 1-35, Dr. Macdougal gives a useful historical account 
which includes notices of nearly of the more important re- 
searches bearing upon the subject, from Ray ed Hales onward to 
the beginning of the present centur 
e remainder of the first two hundred pages contains a detailed 
account of the — 8 experiments on nearly one hu neg different 
species. The arrangement is an alphabetical one, under t nae 
of the plant whisk! formed the subject of experiment. As t 
nomenclature is neo-American, the English plant physiologist will 
perhaps fail to recognize well-known plants under such strange 
names as Apios Apios “Ma em., Bicuculla Cueulara Millsp., Hypopitys 
Hypopitys Small, or Vagnera stellata Morong. It would have been 
kind if the author, having salved his conscience by use of the new 
name, had also included the Linnean name and given a cross 
reference in his table of contents. 
he chapter on ‘General Considerations,” which follows, 
supplies a useful correlation of the results based on the experi- 
ments, details of which have been given = the preceding pages, 
and includes also critical remarks on work of other observers: the 
genaval student of botany will find this chapter a helpful one. The 
remaining pages of the text, 280-309, comprise several short 
chapters. ‘Theories as to the Nature of Etiolation” is a brief 
résumé of explanations advanced by previous workers. ‘‘ Morpho- 
genic Influence of Light and Darkness” follows. Examination of 
the facts obtained by absolute etiolations shows that no one of the 
theories recorded in the preceding section is capable of general 
application to the behaviour of all plants in dar 
phenomena of etiolation rest upon, and consist in, the behaviour of 
ain 
also chapters on the ‘Influence of Etiolation upon Chemical Com- 
position”’ and ‘ ‘The Rate and Mode of Growth as affected by Light 
and 
a! 
The cee part of the work is admirably epee ae by 
numerous drawi age from nature, from photographs, and from 
microscopic sectio: 
Dr. Ew art’s wre on protoplasmic streaming formed the subject 
of a paper read early last year before the Royal Society, by whose 
aid the author has been enabled to publish it in the form of a 
separate treatise. It embodies the results of a series of observations 
carried on at Leipzig, — and Birmingham between se and 
1902. The subject matter " under two 
* Figen and penrtres comprising a discussion re those pheno. 
