ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
231 
y, General. 
Effects of Fog on Plants.* — Prof. F. W. Oliver records the results of 
a large number of observations on the effects of urban fog on cultivated 
plants. The foliage is affected chiefly by the decrease of light, which 
causes a withdrawal of starch from the chlorophyll-corpuscles ; by the 
action of acids, especially sulphurous ; and by the action of organic 
substances contained in the sooty deposit, chiefly phenol and some form 
of pyridine. In addition to its directly poisonous effect, sulphurous acid 
acts by diminishing transpiration. With flowers the period of expansion 
appears to be an especially sensitive time. The effects on them of fogs 
may be referred to plasmolysis, loss of colour, a yellowing due to oil, 
and a browning, caused by a fine precipitate in the protoplasm. Mono- 
cotyledons suffer from fog less than Dicotyledons, and Ferns much less 
still. 
Insectivorous Habit of Dionsea-t — From observation of Dionsea 
muscijpula in its native habitat, Mr. B. Dean states that the position of 
the trap is more adapted for the capture of creeping than of winged 
insects. A far larger quantity of the remains of the former were found 
in the traps than of the latter, the escape of larger winged insects being 
also facilitated by the slowness with which the trap acts. The leaves 
frequently close on vegetable and even on inorganic objects when 
captured. After digestion has taken place, the position of the trap, 
when re-opened, allows the undigested particles to fall to the ground. 
The sensitiveness is not confined to the bristles, but belongs in a 
modified degree to the whole of the upper surface of the leaf. 
Perfume of the Violet.J — MM. F. Tiemann and P. Kruger have 
analysed the perfume which occurs both in the flower of the violet and 
in the rhizome of Iris, and find it to be a cetone with the formula 
C 13 H 20 O, to which they give the name irone. The mode of extraction 
of irone, and its chemical properties and compounds, are described. 
B. CRYPTOGAMIA. 
Muscineae. 
New Genera of Musci. — In a collection of Mosses from Japan 
M. E. Bescherelle § describes a number of new species, and the following 
new genera : — 
Fauriella (Leskeeae). Plantae tenellae, repentes et adscendentes, 
fragiles, molles, glaucovirides, ramis erectis, ramulis patentibus plu- 
mosis ; folia ovata, cymbiformia, ecostata, subtus papillosa, serrata v. 
obsolete dentata, areolatione rhomboidea ; capsula minuta, erecta, post 
sporosim cernua et horizontalis, operculo conico, apiculato ; peristomii 
dentes colorati, dense trabeculati, siccitate incurvi, interni membrana 
brevi perfecti, siccitate erecti ; cilia breviora, terna in uno coalita ; 
calyptra cucullata, elongata, contorquata, laevis, 
* Journ. R. Hort. Soc., xvi. (1893), 59 pp. 
f Trans. New York Acad. Sci., xii. (18‘J3; pp. 9-17. 
j Comptes Rendus, cxvii. (1893) pp. 548-52, and Atti R. Accad. Lincei, ii. (1893) 
pp. 350-4. § Ann. Sci. Nat. (Bot.), xvii. (1893) pp. 327-93. 
