SCIENCE. 
265 
be carried through absolute alcohol into turpentine, and ] 
mounted in balsam at any time thereafter. If successful in 
this staining you will have the pith cells in red, the spiral 
tissue in blue, the wood cells in purple and the stellate 
crystals in green or yellow. 
But the chief objects of interest to the microscopists in | 
the vegetation of Florida, are the insectivorous plants. Not 
only are they more abundant, and, as I think, more per- 
fectly developed in the central lake regions of Florida, but 
some varieties are found there differing, it seems to me, 
from any found elsewhere. I desire particularly to mention 
one which I discovered, and which perhaps might be en- 
titled to rank as a new species. 
In a lagoon-like basin at the side of a small lake near 
Lake Harris, in water from two to three feet deep, I found 
numerous specimens of the insectivorous plant known as 
the Drosera or Sun-dew, growing thriftily and floating about 
among the scattered water-weeds, without any attachment 
whatever, indeed with very little root of any kind, the dead 
leaves that hung down in the water seeming both to buoy 
it up and to hold it upright. This plant differs from all the 
described species of Drosera, so far as I have been able to 
to ascertain, in having an upright, leaf-bearing stem from 
four to five inches long, in floating free on the water, and in 
having unusually long, vigorous and numerous leaves. As 
I never found this floating Drosera in any other location, 
and as there was an abundance of the ordinary Drosera 
longifolia growing on the adjoining shore, I could not resist 
the suspicion that at this very spot in some past time a 
plant of the longifolia had by accident become uprooted, 
and floated out on the water — that finding it could capture 
insects even better on the water than crowded among shore 
plants, it adapted itself permanently to its new location 
and modes of growth. It appeared to me quite within the 
bounds of probability that here was an instance of the evo- 
lution of a species in loco. 
The Drosera or “ sun-dew ” is found on the margins of 
nearly all small ponds and permanently wet places through- 
out the south. It is a small red plant, growing close to the 
ground, and glistening in the sunlight. Its little whorl of' 
expanded leaves forms a circlet as beautiful as any flower, 
and often so very small that I have frequently mounted 
whole plants with flower-stalk and buds on one slide. 
Each leaf of the Drosera has, spread out on its upper sur- 
face and edges, from two to three hundred arms, called 
tentacles because endowed with the power of motion, and 
of such varying lengths that when naturally incurved their 
ends just meet at the centre of the leaf. Each tentacle 
has at its extremity a pad, like an extended palm, with a 
ridge raised lengthwise upon it, and in this palm is a bundle 
of spiral vessels connected with the same tissues in the 
leaf. Nowall the tentacles secrete and exude from the glands 
at their ends a little drop of a very adhesive fluid ; and the 
glistening of these drops in the sunlight on their usually 
bright red back-ground, gives to the plant its beauty and its 
name of the “ sun-dew.” An insect attracted to and alight- 
ing on these leaves is inevitably held fast. The tentacles 
by which it is held very soon begin to bend towards the 
centre of the leaf, carrying the fly with them. Then in some 
mysterious way, intelligence is communicated to the other 
tentacles, and they too begin to turn towards the centre of 
the leaf, in the course ol an hour or two completely cover- 
ing the captural prey. If the insect is caught entirely on 
one side of the leaf, then only the tentacles of that side in- 
flect. The glands, after envelopment, exude a gastric fluid 
which dissolves the nitrogenous matter in the body, after 
which, by another change of function, they absorb and carry 
down into the plant all this nutritious little feast. In the 
course of three or four days the tentacles again expand and 
prepare themselves for another capture. 
There are several reasons which lead me to believe that 
these unique and most wonderful organs of the Drosera are 
a direct and special development from the common, simple 
mushroom glands, which are found on many plants, and 
which have for their primary function to absorb moisture ! 
and ammonia from the atmosphere and from rains. I found j 
on the calyx and flower stem of the Drosera an abundance 
of these mushroom glands. Indeed the flower stem with 
its buds furnishes by reason of them, an exceedingly beauti- 
ful object for the microscope, both in a natural state and 
when prepared by double staining. 
I have found it quite a general rule as regards plants, 
that whatever organs, such as stellate hairs or glands, the 
leaves may possess, the calyx and stem of the flower will 
show them in far greater luxuriance and beauty. The 
stellate hairs of the Deutzia, the Crotons, and the Shepher- 
dias are far more numerous and striking on the flower buds 
than on the leaves. The mushroom glands which are found 
on the leaves of the Saxifrage and Pinguicula, are multi- 
plied many fold in number and attraciiveness on the calyx 
and flower stem of these plants. So I regard that this was 
once the case with the Drosera ; and that the mushroom 
glands, which are now found on the flower, were then com- 
mon to the leaves. A process of evolution has transformed 
them on the leaves into those wonderful motile arms 
adapted to the capture of insects, but has left them un- 
changed on the flower, where that function would be of no 
use to the plant. I occasionally find in my preparations a 
solitary mushroom gland among the tentacles of the leaf — 
a remnant of a race that has been supplanted. There is 
found in Portugal a plant very similar to the Drosera, the 
Drosophyllum, which has still only the mushroom glands 
on its leaves, and catches insects in great quantity by load- 
ing them down with the viscid secretion which these glands 
abundantly pour forth. 
To exhibit the very delicate structure of the leaf and ten- 
tacles of the Drosera, it is necessary to color them but 
slightly. The danger will be in over-staining ; therefore, 
after decolorizing and immersing for a few hours in the car- 
mine solution, the specimens should be exposed to only a 
very weak fresh solution of logwood for fifteen or twenty 
minutes. If the anilin blue is resorted to at all, it must be 
in a very weak solution. A mounting of a leaf and a stem 
with flower buds in one cell in camphorated or carbolated 
water, makes a very pretty and complete slide for the Dros- 
era. 
The Utricularia is a floating, carnivorous plant which 
grows in the shallow water of quiet ponds. On the surface 
of the water from five to seven leaves are spread out like 
the spokes of a wheel, and from the centre of these leaves 
the plant sends upward its flower stalk and downward its 
root-like branches, floating freely in the water. Among 
the thickly branching fibres of these long submerged 
stems, are perched innumerable little bladders or 
utricles, not much larger than the head of a pin, 
each provided with a mouth, at the bottom of a sort 
of funnel of bristles, closed with a cunning little trap-lid 
which opens inward, engulfing and imprisoning whatever 
minute creatures or substances may happen to be resting on 
it. In these sacks during the growing season, we will find 
numerous microscopic water fleas, mites and beetles, with 
grains of pine pollen and other floating particles. The 
organic bodies will be found in all stages of digestion, 
showing that the plant derives nourishment from such cap- 
tured prey ; and apparently its only means of livelihood is 
trapping. 
When taken from the water and dried under slight pres- 
sure, the submerged portions of the Utricularia will be 
found literally covered with diatoms ; and many very inter- 
esting chrysalids of water-insects will be found attached to 
them. These will all be washed off if the plant is bleached 
in chlorinated soda.. To preserve them it will be necessary 
to remove the color in alcohol, and besides to handle very 
carefully. The staining can only be single ; and I have 
found a weak solution of eosin in water, to be the best 
material for coloring, showing at the same time the structure 
of the utricles and the captures contained in them. Speci- 
mens of new growths, showing the just forming utricles 
and the peculiar circinate mode of growth, should be in- 
cluded on the slide. The mounting should be in campho- 
rated water. 
The Pinguicula, another of the insectivorous plants, is 
found abundantly on the more open plains, and not far from 
wet places. It is a compact rosette of very light green 
leaves, growing close to the ground, from the centre of 
which rises a single flower-stalk, eight or ten inches high , 
The leaves have their edges turned up, forming a shallow 
trough, and on the upper surface are mushroom glands, 
which exude a viscid secretion. Insects are caught and 
