1913] CURRENT LITERATURE 253 
show a periodicity in their starch content which coincides with the recurrence 
of daylight and darkness, that locally darkened areas of the leaf blade soon 
show a deficiency in starch content, and that when the stomata are closed 
with cocoa butter starch formation does not occur. Further it appears that 
shoots free from starch soon showed the presence of that substance if placed 
in sunlight in an atmosphere containing CO., but controls, also in sunlight 
but in an atmosphere without CO.,, pares no —— Support i is also given 
to the contention that many of these plants re their 
hosts by the fact that they will thrive as root parasites upon annuals which 
have no starch or sugar stored in their subterranean organs.—Gro. D, FULLER. 
Phosphorescence in plants 
Motiscu! has issued a second and enlarged edition of his work on phos- 
phorescing plants. The book is very simply and interestingly written, and 
brings up to date his own extensive work in this field as well as the work of 
_ other investigators. The first chapter answers negatively the question 
“are there phosphorescing algae ?”, and shows that such appearances are due 
to light reflection or to animals living on the algae. The second chapter 
gives the evidence for the existence of phosphorescence in marine Peridineae 
and for its absence in fresh water forms. The third chapter deals at length 
with the phenomenon in fungi, both Hyphomycetes and bacteria, and the 
fourth shows the relation of salts and temperature to the light production in 
bacteria. The fifth treats of the nutrition, phosphorescing, and growth of 
the light-producing fungi, and the sixth with the manner in which light is 
Produced. Phosphorescence is an oxidation process demanding a minima] 
though very small partial pressure of oxygen. There is no convincing evi- 
dence for any direct relation between respiration and ia ste much 
less for the latter being produced by the former. The living cell produces a 
substance, photogen, which phosphoresces in the presence of water and free 
oxygen. In the higher fungi and bacteria, in contrast to many animals, the 
Phosphorescing has never been obtained extracellularly. In chapter seven 
the author gives the spectra and other characters of the light produced by 
various fungi 
The bacterial light is of sufficient intensity and of proper quality to render 
photographic work possible by it as the sole source of light. It will cause 
heliotropic response in various seedlings and fungi, and lead to chlorophyll 
Production, detectable by the spectroscope though not sufficient for visible 
8teening. The light is not capable of penetrating opaque objects, as some 
workers have probably wrongly claimed for light produced by various animals. 
In contrast to the situation with many animals, MoLiscH cannot discover 
any biological significance of light production in plants. The last chapter 
ee 
ScH, Hans, Leuchtende segue: eine physiologische Studie. viii+193. 
bls. 2. tis: 18. Teun: Gustav Fischer. 1912. 
