70 _ BOTANICAL GAZETTE [JANUARY 
while a third group had the corollas removed and was hand-pollinated. Instead 
of noting insect visits, the seeds from an equai number of flowers of the three 
groups were weighed. The average for each fruit was 117™ in normal insect- 
visited flowers, 115™S in the hand-pollinated flowers deprived of corollas, and 
but 50™8 in the flowers deprived of corollas, which were left free for insect visita- 
tion. In other words a poppy with showy flowers produces more than twice as 
much seed as a poppy without showy flowers, when left free to insect visits. 
Thus GiLTay was at first led to doubt PLATEAv’s conclusions. However, fur- — 
ther experiments produced a modification of his views, since it was noted that 
insects, and particularly bees, pay less and less attention each day to showy 
flower groups where no nectar is present, while they pay more and more attention 
each day to inconspicuous flower groups, where nectar is present. It would 
seem, then, that PLaTrau failed to see the earlier visits of his insects, or at least ( 
failed to discriminate in his results between the earlier and later visits, while f- 
ANDREAE, in general, seems to have concluded his experiments too soon.—H. C. § 
CowLEs. 
Scumipt ° defines the mangrove association as that made up of tree-like ever- 
mn plants which live near the strand of sea and estuary where the ground i 
constantly or at regular intervals flooded with salt or brackish water. Owing 
to its peculiar development and mode of life this is the most characteristic and 
well defined association known. The English “tidal forest” or the Holland 
“‘vlordborsch”’ is suggested as preferable to mangrove association, the former 
expressing exactly what is characteristic of the formation. The Barringtonia 
association (Schimper) borders closely upon the mangrove. As a rule, however, 
they are quite distinct, the Barringtonia being found on a higher level where the 
tidal water does not re 
Light plays an important part in determining the position of the leaves and 
branches? By placing ten leaves horizontal and ten others upright in the normal |} 
light of the mangrove forest it was found that disorganization of the chlorophyll 
took place in one-half to two minutes in the former, while after thirty minutes 
only a partial disorganization occurred in the latter. By assuming the vertical 
position the buds and leaves expose the least surface to the direct rays of the 
sun. ‘The relative intensity of the light according to the exposure of photographic 
paper is for the open sea one-fourth to one-half second, in the mangrove two 
seconds, and in the inland jungle ninety seconds. Hence it is seen that the light 
. very —— in ne mene swlpeeeit In the inland jungle the undergrowth : 
t light, but so as to get the most, 7. e., 
ina Saateoneal position. : 
The major part of the article is devoted to taxonomic descriptions, es { 
being laid upon the arrangement and character of the buds, branches, and leaves. 
* SCHMIDT, Jous., Bidrag til Kundskab om Skuddene hos den gamle Verdens — 
(Contribution to the knowledge of the shoots of mangroves in the 
old oaks Rot. Tidsskrift 26: 1-113. Bs. 46. 1904. 
