No. 377.] REVIEWS OF RECENT LITERATURE. 355 
The isolation of the two substances — the reducing and the oxidiz- 
ing — was now attempted. The former is not changed by boiling or 
by the action of chloroform, and is soluble in alcohol; the latter is 
destroyed by heat, is unchanged by chloroform, is insoluble in 
alcohol, and can be extracted from the triturated cells by water. A 
large number of root-tips of Vicia faba were first rubbed up with 
water until no fragments remained. The aqueous extract was filtered, 
and to the filtrate alcohol was added. A precipitate was formed 
which had all the properties of the oxidizing substance. It is highly 
probable that it belongs to the category of oxidation ferments. -To 
get the reducing substance, the preceding solution was filtered to 
eliminate the alcoholic precipitate. The filtrate had all the proper- 
ties of the reducing substance. A further study indicated that it 
belonged to the aromatic organic substances, many of which have an 
intense reducing action, and are hence used in photography. 
Thus, geotropic stimulation of the root-tip produces chemical 
changes leading to the increase of a reducing substance of aromatic 
nature, and to a diminution in the amount of an oxidizing ferment. 
Dissimilar Reciprocal Crosses. — It has been observed in many 
cases that the two hybrids AQ X Bg and BỌ X A@ are dissimilar. 
In the current Heft of the /enaische Zeitschrift is an interesting note 
by the late Fitz Miiller-Desterro, serving to explain this phenomenon 
in a single case, the hybrid of Ruellia formosa and &. silvaccola, The 
` parent flowers differ in that those of R. formosa are a dark, luminous 
red, while those of 2. si/vaccola are a clear, faint red. The hybrid 
R. silvaccola x formosa is of a beautiful red, more like the red 
of R. formosa than of R. silvaccola; and R. SormosaQ X stlvaccola § 
is of a cloudy mixed color, with more or less extensive smutty 
blotches. The difference of color is due to the fact that the egg 
cell only, and not the male cell, transmits the chromatophores upon 
which the color depends ; hence, the hybrid X.. si/vaccolaQ X for- 
mosaĝ received chromatophores from s#/vaccola only, while for- 
mosa X silvaccolag received them from formosa only. (This result 
does not, however, fully explain the observed facts of color in the 
hybrid.) The important conclusion is now drawn that in this case 
the qualities of the hybrid depend, not alone on the germ plasm in 
a strict sense, but also on certain living included particles. 
Scientific Agriculture. — One of the most handy books of relit- 
ence which has appeared of late is Henry’s Feeds and Feeding.’ 
1 Henry, W. A. Feeds and Feeding. A handbook for the student and stock- 
man. Madison, Wis., 1898. _Published by the author. 8vo, vi + 6 
