72 THE AUSTRALIAN NATURALIST. 
ery in the heart of a Tweed scrub, because it is beyond all 
understanding. / 
PLANTS THAT GO TO SLEEP, AND TWINING 
HABITS OF CERTAIN PLANTS IN. 
PORT JACKSON). 
(Abstract. ) 
By Edwin Cheel. 
The phenomenon of leaf movement was observed as 
early as the days of Pliny, for we find records were made 
of certain movements of plant-life in his time. 
Carl von Linné also observed that certain plants closed 
their flowers or folded their leaflets at night, and opened 
them in the morning at day-break; and his observations 
are published in his “‘Somnus Plantarum.’’ Since Lin- 
naeus published his work, many important memoirs have 
appeared, including such excellent works as those pub- 
lished by Charles Darwin, Pfeffer, Ulrich, and Sachs. 
In the latter’s works, plant movement is divided into 
three classes, namely, (1) periodic, automatic, or spon- 
taneous; (2) those influenced by light and heat—the 
diurnal and nocturnal; and (3) those due to concussion 
or touch. 
In the first class, such well-known plants as Des- 
modium gyrans may be grouped, which is quite familiar 
to a great number of plant-lovers. 
In the second class we may group those plants which 
close their florets in the evening, such as the garden 
daisies. 
The third group includes such plants as the familiar 
trigger-plants (Stylidiwm spp.), or ‘‘Ant Orchid’’ (Cale- 
ana major); and we may include the well-known sensi- 
tive plant (Mimosa pudica) in this latter group. 
The opening of the flowers or unfolding of the leaf- 
lets in the morning, and the closing of same in the even- 
ing, such as we see in the ‘‘Native Yellow Wood Sorrel’’ 
(Oxalis corniculatus), is, without doubt, something very 
suggestive. if not representative of sleep, as to warrant: the 
appellation of ‘‘sleep’’ and ‘‘waking.’’ 
The hour at which certain flowers close and re-open 
is so exact that ‘‘floral clocks’? have in former days 
taken a prominent place, 
