264 
SCIENCE. 
have peculiar organs, such as absorbing glands, glandular 
hairs, stellate hairs, protecting scales, and a variety of other 
special appendages. All these have been developed by 
time and necessity, in remarkable profusion and perfection 
in the vegetation of Southern Florida. Although the 
meagre soil produces no nutritious grasses, and scarcely 
enough of an honest vegetation to keep an herbivorous an- 
imal from starving ; yet there is an abundant flora such as 
it is — air plants, parasitic growths, insectivorous plants, 
and strange herbs seeking a livelihood in any other way 
than the good old honest one of growing from their roots. 
It is this fact which makes the microscopia! interest of bot- 
anical researches in Central Florida. One can scarcely 
examine with a two-thirds objective the flowers, leaves or 
stems of any plant growing there without discovering some 
beautiful or striking modification of plant hairs, or scales, 
or glands, or other absorbing or secreting organs. 
We will notice first the Onosmodium as found in Florida 
— O. virginianum. It grows from Virginia south, but is 
more glandular I think, in Florida than anywhere else. It 
will be almost the first plant one would stop to observe on 
entering the pine woods — a dark-green, narrow-leaved, bi- 
ennial herb ; its straight stem of the second year’s growth, 
about a foot high, bearing a raceme-like cluster of flowers, 
coiled at the end, and straightening out as the flowers ex- 
pand. The leaves of this plant are thickly studded on both 
sides with stiff transparent hairs, lying nearly flat on the 
surface, and all pointing toward the tip end of the leaf. 
At the base of each hair is a cluster of glandular cells, 
amounting sometimes to fifty or more, arranged in beauti- 
ful geometrical forms. When pressed and dried in the her- 
barium, the body of the leaf turns to a dark green, almost 
black, and on this back-ground, with a half-inch objective, 
the hairs stand out like sculptured glass, and the glands 
like mosaics of purest pearls. I think it is the most at- 
tractive opaque object that can be shown under the micro- 
scope. 
That these glandular cells, covering, as the}' do, nearly 
half the surface of the leaves, especially the upper surface, 
and differing from all other vegetable cells, subserve an im- 
portant purpose in the sustenance of the plant, there cannot 
be any doubt ; but just what that purpose is, or what is the 
mode of operation, I think, has never been ascertained. 
In the same locality will very likely be found the most 
beautiful of all the Croton plants, the C. argyranthcmum. 
Unlike the other Crotons, which are bushes, this is an herb 
growing only about a foot high, with a milky sap which ex- 
udes when the stem is broken. The leaves are silvery, 
verging in some cases to a bronze color, and are thickly 
covered on the upper side with most remarkable and beau- 
tiful stellate scales. The flower-buds and stem, when 
pressed, make much more beautiful opaque objects than the 
leaves. 
The object of these scales is, without doubt, to prevent 
the too rapid evaporation of the moisture stored up in the 
plant. They are the exquisitely woven blankets which pre- 
serve the precious juices so laboriously gathered. The 
same kind of covering is spread over the leaves and stems 
of all the air-plants of Florida, and doubtless for the same 
purpose. The well-known Florida moss, although not a 
moss, but a member of the pine-apple family ( Tillandsia 
usneoides), is an exceedingly beautiful object under the mic- 
roscope. Each hanging stem is overlaid with filmy white 
scales, every one of which is fastened in its place by what 
would seem to be the stamp of some miniature seal on 
golden-tinted wax. This plant as ordinarily seen on the 
live-oaks near cities, is a dirty-looking and unattractive ob- 
ject, and goes by the name of “ black moss.” But in out- 
of-the-way places, removed from the du -t and smoke of se,- 
tled localities, it is pearly white, and exceedingly beautiful 
both to the naked eye and under any power of magnifica- 
tion. Florida moss should be preserved with only a very 
slight pressure, just enough to make the threads lie straight. 
After it has dried in this way, small cuttings maybe mount- 
ed in the ordinary cells for opaque mounting. 
On the high banks of the lake, and in the adjoining 
fields may be found the large-leaved and vigorous-growing 
Calicarpa (C. Ameticana), sometimes called the French mui' 
berry, a bush growing some five or six feet in height. The 
under side of the leaves of this plant are nearly covered 
with little round, yellow, sessile glands, flattened on top 
and marked off into eight ten sections by ribs like those on 
a melon. They are in immense numbers — something like 
thirty thousand to the square inch — over half a million on a 
good-sized leaf. Under a light net-work of branching 
glandular hairs, viewed with a two-thirds objective, these 
polished ambor-colored disks glisten like a spangle of 
golden beads. The same kind of glands is found on the 
leaves of many other shrubs in Florida — the sweet myrtle 
( Myrica cerifera), the low-ground bl ueberry ( Vaccinium te- 
ns Hum) & certain bush or dwarf hickory ( Cary a glabra) and 
some others. These glands have been variously called 
resin dots, resin glands and odoriferous glands. So far as 
I can judge, however, they are not connected with anv res- 
inous or odoriferous secretions. From their almost perfect 
resemblance to the terminal bulb of the mushroon glands 
of the Pinguicula and Drosera, which are known to be ab- 
sorbing glands, the probability is that these also serve to 
absorb moisture and ammonia from the atmosphere and 
from rains. Although I am free to acknowledge that the 
position of the glands, being for the most part on the un- 
der side of the leaves, militates somewhat against this view 
of their purpose. 
Great care will have to be taken in pressing and drying 
vegetable specimens in the moist climate of Florida. The 
little threads of the mould fungus will be sure to creep over 
the surface of the leaves, spoiling them for microscopical 
material, if they are not quickly and effectually dried. For 
this purpose it is well to have a good supply of the bibulous 
botanical paper, and to change the specimens every day to 
fresh sheets for at least four or five days. The sheets, after 
being once used, should be spread out in the sun to dry. A 
weight of about thirty pounds may be used for the pres- 
sure. 
The objects heretofore mentioned are all for opaque 
mounting. Almost every preparer of slides has his own 
favorite method for this kind of work. I myself prefer the 
use of the transparent shellac cells. Clarified shellac is 
dissolved in alcohol, and filtered through cotton-wool un- 
der a bell-glass, and with the application of heat. The solu- 
tion is evaporated down until it is so thick that it will only 
just run — almost a jelly. In this cond : tion it can be put 
on a slide with a camel’s hair brush on the turn-table, and 
very quickly worked up into a ring with the point of a 
knife, used first on the inside to make the cell of the size 
wanted, and then on the outside to turn the cement up into 
a compact ring. Two or three applications of the cement, 
with intervals of a day or two after each, will make 
cells of sufficient depth for all ordinary specimens. 
These cells dry quite slowly ; and if artificial heat is 
used it must be increased only very gradually, other- 
wise vapor of alcohol bubbles wiil make their appearance 
in them. A small ring of Brunswick black may be made 
in the inside of the cell, to which, when thoroughly dry, 
the object may be fastened with a very little liquid 
marine glue. In this case both sides of the leaf can be 
seen, which is often desirable. In all opaque mountings a 
minute aperture should in some way be left open into the 
inside of the cell, so that it shall not be hermetically sealed 
up. This little precaution will save an innumerable num- 
ber of failures. 
The collector in Florida will not fail to secure a supply 
of the-leaf stems of the castor oil plant ( Ricinus communis ). 
In regions beyond the influence of frosts, this plant grows 
continuously from year to year, and becomes quite a tree. 
It is only in such a growth that the spiral tissue of the 
fibro-vascular bundles is fully perfected. The castor oil 
plants grown in our climate during one short season, will 
furnish very little spiral tissue, mostly spotted ducts and 
scalariform cells. There is no more beautiful object for 
multiple staining than thin longitudinal sections through 
the woody fiber, the vascular tissues, and the pith cells of 
well matured leaf-stems of the castor oil plant. I will 
briefly describe my process of making these stainings. 
After being decolorized in chlorinated soda, the sections 
may be left for half a day or more in a solution of carmine 
in water containing a few drops of aqua ammonias ; then for 
half an hour in a rather weak solution of extract of logwood 
in alum water, and finally 10 to 15 minutes in a weak solu- 
tion of anilin violet or blue in alcohol. From this they can 
