No. 432.] NOTES AND LITERATURE. 983 
Leaves of aquatics. — McCallum! gives the results of experiments 
designed to discover the factors determining the production of the 
well-known air and water forms of leaves in Proserpinaca palustris. 
After describing the form and anatomy of the two types of leaves, 
he gives the results of his experiments, which seem to show that the 
production of the submerged, much-dissected type, or the aérial, 
simply serrate type, is not determined by difference in illumination, 
nutrition, depth of water, temperature, stimulating influence of salts, 
variation of concentration of CO, or O, or contact stimulus. When, 
however, the plants were grown in a saturated atmosphere, a type of 
leaf very close to the regular submerged type is produced, and when 
plants grown under water are subjected to artificial transpiration 
induced by a change in osmotic pressure secured by a solution of 
mineral salts in the water, the air type of leaf was produced. 
Further experiments, the results of which will be presented later, 
are in progress. J. A. Harris. 
Notes. — The American Journal of Pharmacy for September con- 
tains an article on ZZyoseyamus muticus, by Nagelvoort, and an 
account of the drug and medicinal-plant investigations in the 
Department of Agriculture, by True. 
In the American Journal of Science for September, Fernald dis- 
cusses the relationship of some American and Old-World birches; 
Sellards describes the fertile fronds of Crossotheca and Myriotheca, 
and the spores of other Carboniferous ferns, and also the validity 
of Jdiophyllum rotundifolium, a fossil plant from the Coal Measures. 
The Bulletin of the Torrey Botanical Club for August contains the 
following articles: Slosson, “ The Origin of Asplenium ebenoides ” 
(including the results of artificial hybridization of Camptosorus rizo- 
phyllus and Asplenium platyneuron, and confirming the assumed 
hybrid nature of 4. ebenoides, except that the artificial hybrids have ¢ 
not yet been made to fruit); Evans, “ Hepatice of Puerto Rico" 
White, * The Saltatory Origin of Species"; and Eastwood, “ New 
Western Plants." 
.In Engler's Botanische Jahrbücher of August 29 are published the 
conclusion of Miss Perkins's “ Beiträge zur Kenntnis der Stryraca- 
ceæ”; a monographic synopsis of the genus Lisianthus, by the same 
1 McCallum, W. B. On the Nature of the Stimulus causing the Change of 
Form and Structure i i palustris, Botanical Gazette, vol xxxiv 
(August, 1902), pp. 93-108, Figs. 1-10. 
