a) 
1876.] Botany. 299 
GENERAL NOTES. 
BOTANY.! 
On tue Rate or Movement or WATER IN Prants. — This subject 
has been frequently investigated since the time of Hales and Bonnet. 
Professor Sachs, of Wiirzburg, gave, as the result of his observations, 
the rate of 23 centimetres an hour. McNab, in 1871, made use of a 
solution of a salt of. lithium, and traced it in-its course through the 
plant, coming to the conclusion that the rate was 46 centimetres an hour. 
These values are regarded by Sachs himself and others as too low. The 
methods are regarded by Professor Pfitzer, of Heidelberg, as unsatisfac- 
tory, and he suggested in 1873° another which yielded very remarkable 
results. He allowed the soil in some flower-pots containing plants to 
dry so far as to cause drooping of the leaves. Then he noted the posi- 
tion of the leaves by means of needle points, and watered the soil freely. 
The leaves recovered their former positions rapidly, and the times were 
observed. The rate of 5 metres an hour was the highest noted. In 
Justicia Adhatoda leaves 254 centimetres above the ground moved in 
three minutes after the soil was watered. In 1874 McNab repeated the 
lithium experiments and obtained a higher rate than before, nearly 40 
inches in the hour. Looking upon this as too low, Pfitzer has again ex- 
perimented, this time with lithium nitrate. The water employed con- 
tained one half of one per cent. of the salt. The plants used were cut 
under the solution, and the cut end immersed therein for a while. Upon 
removal the plant was cut in lateral halves from above downward, and 
the parts were tested spectroscopically. Twigs of Philadelphus gave 
4}, Amarantus 6, and Helianthus 10 metres in the hour. The highest 
rate observed was in the case of a sunflower with leaves in bright sun- 
light ; here it was 22 metres in the hour.: The results of later observa- 
tions are promised. 
Tue Inrivence or Ligut on tHe Conor or Frowers.— It was 
shown by Sachs a dozen years ago that the blossoms of many plants can 
develop normally in perfect darkness, Plants which have a good supply 
of elaborated material stored up in bulbs or tubers were observed to 
have flowers of normal shape and color, even when all the leaves had 
grown and the flower-buds opened in a dark room. If the buds are 
inclosed in Opaque cases, but the leaves exposed to sunlight so that 
assimilation is unhindered, the color and shape of the flowers remain 
normal. There were noticed by Sachs a few slight exceptions. Com- 
mon nasturtium blooming in the dark had flowers more yellow than usual ; 
wall-flower had smaller and brighter yellow blossoms than those which 
Opened in the light; scarlet-runner, brilliant flesh-red flowers; large 
snapdragon, usually having flowers of deepest red, had, when blooming 
m the dark, corollas which were white blotched with rose, and on the 
1 Conducted by Pror. G. L, GOODALE. 
