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1899] CURRENT LITERATURE 4gI 
made by other botanists. Golinski® reports male cells in pollen grains and 
tubes of Triticum and other grasses, which “are not unlike the antherozoids 
of a fern or of Chara.” His figures, however, are very unsatisfactory. 
Mottier™ figures a coiled male nucleus closely applied to the female, in 
Lilium Martagon. Indications of a male nucleus fusing with the polars have 
been found in Lilium Philadelphicum by some students in the Hull Botanical 
Laboratory during this last year. The present writer has found elongated, 
and often spirally twisted male cells in the pollen of Silphium, the figures 
for which are soon to be published. It would seem, then, that such reminiscent 
forms of male cells are to be looked for almost anywhere, if they can be 
found in such widely separated groups as the Graminez, Liliacee, and Com- 
posite.—W. D. MERRELL. 
OVERTON’S STUDIES on color have been previously referred to in this 
journal.” His results have now been more fully published and furnish some 
interesting data."3 The author noticed that a red coloration appeared in 
leaves of Hydrocharis grown in a sugar solution, and that the colors deepened 
as the solution became more concentrated by evaporation. Knowing also 
that alpine plants are more highly colored than plants in the lowlands and 
that low temperatures cause an increase of sugar at the expense of starch, 
Overton felt that it was worth while to make some experimental studies as to 
the connection between red cell sap and sugar. 
Elaborate and varied experiments were made on Hydrocharis. In 
water cultures the colors were developed by increasing the light sufficiently 
or decreasing the heat, light and heat being opposing factors. Where the 
light and heat conditions were such as to produce no red coloration in water 
cultures, 2 per cent. invert sugar solutions induced colors within three days. 
Both old and new leaves are affected and the colors deepen day by day. Plants 
grown in sugar solutions bloom sooner than when grown in water. Experi- 
ments with various other sugars resulted similarly. The color stuff is mainly 
in the palisades and may be precipitated by coffein or antipyrin in a form 
resembling precipitates of tannin stuffs. Utricularia, Elodea, Trapa, and 
other water plants gave similar results. Experiments were also made on cut 
“stems of Lilium, Ilex, and other land plants; colors were obtained in sugar 
solutions but not in water cultures. 
The author concludes that the formation of red cell sap is closely con- 
nected, in most of the plants studied, with a rich content in sugar. Low 
* Bot. Cent. 55 : 1-17, 65-72, 129-135. 1893. 
Jahrb. f. wiss. Bot. 31 : 125-158. 1898. 
* BoT. GAZ. 27:229. 1899. : 
*3Beobachtungen und Versuche iiber das Auftreten von rothem Zellsaft bei 
Pflanzen. Jahrb. f. wiss. Bot. 33: 171-231. 1899. 
