256 THE JOURNAL OF BOTANY 
text—a remark which bat oe to miahy of the British species 
the arrangemen the Student’ s Flora, and are thus dissociated 
from eg “text, save i i a reference in the index, which, by the 
way, is far from com lete. The text contains misprints—e. g. 
vir ie anthropophera ” (p. 84)—which we do not think were in 
the original issue, and at least one of the ghee lettered 
“Luzula sylvatica”—is inaccurately named, both on the plate 
(sliv.) and in the appendix. We cannot refrain from expressin 
surprise that a body of the seaming of the Religious Stent Society 
should publish a book in every respect so unsatisfacto 
Light-flashes from Flowers.—In a or eee tibdar “ Messrs. 
G. Fischer (Jena, 1914, 8vo, pp. 1-53, 1 fig.) F. A. W. Thomas dis- 
cusses the light- flashes of flowers at twilight te were observed 
by Linnwus’s daughter ee and have also been described 
by Goethe and ot thers. Thes appearances are to be ascribed to 
optical illusion. The sivaceais of the outer part of the retina 
renders it sensitive to different seeasiiitaee of light but not to 
colour ; the fovea, 7.e. the centre of the yellow spot, on the other 
hand, is the region of keenest perception of colour.; Ack giles 
when in a certain degree of twilight the image of a red flower 
moves from the peripheral parts of the retina to the Cie the red 
colour appears to become more vivid. a the a ok the 
waves of light approach the length roducing maximum 
migie gS in those parts of the retina apactally adapted to anbkiees, 
o that a distinct reflection of the background of the flower is 
Picived. and this combines with the more vivid perception of 
red to give an impression of lightning. This ol ase is 
ingenitiad if the fading light is bluish. green in colour 
The Journal of the Linnean Society (xlii. no. 988) issued 
May 15 contains papers on the Structure of the Wood of Hima- 
layan Junipers, by W. Rushton ; a contribution to the Flora of 
on Tristichacee, illi is, who “regards Tristicha, 
hitherto referred to Padraic, as the type of a new natural 
family. 
Tue Journal of the Department of Agriculture for Ireland 
issued in onde last contains two important contributions by ae 
pecan on To nooo-growing jiseland—s subject which 
received attention as long ago as 1830, a treatise on the 
Tobacco Plant was published by Phonike. Bouiiacn (d. 1849), who 
had studied tobacco-gro wing in America in 1817. 
