10S 
THE AUSTRALIAN BEEKEEPERS’ -JOURNAL. 
Having thus rapidly sketched the varying con- 
ditions of nectar from the moment of its seizure 
by the bee from its tiny resting-place upon the 
plant to its use by us as food, let 11 s try to con- 
duct our readers through what we consider the 
alphabet of its growth, the spelling of its 
mysterious constitutions, for the marvels of the 
chemistry applied in its cell laboratory we 
perhaps shall never attain to. In order to under- 
stand all action, a rough and crude outline of a 
portion of structural botany may be here neces- 
sary. All plants consist of a number of cells of 
various shapes (more commonly circular or egg- 
shaped), and it is by the growth, subdivision, 
and multiplication of these cells that the 
structure of the plant is increased. The cells 
reach from the naked white cells at the ex- 
tremities of roots to the cells at the terminal 
points of the growing bud, including the cells 
filled with coloured sap on the flower petals, and 
others found in fruits or seeds, each cell doing 
its work in wonderful sequence and order. A 
growing nucleus, moving in protoplasm, sur- 
rounded by fluids, and confined by a skin, is the 
normal condition of such cells as we are dealing 
with in this article, therefore, to illustrate the 
circulation of the sap we ultimately meet as 
nectar, we will proceed to describe what is 
termed ‘osmose' I the mixing of substance 
through a dividing film or partition). Suppose we 
fill a common bladder with honey, tying in the 
bladder neck a glass tube, and plunge the whole 
into a vessel of water. The different densities of 
the two substances divided by the permeable wall 
will gradually be adjusted, but for a long time 
the water will pass into the bladder, causing a 
rise in the tube. This is endosmose, and is 
similar to the action of the root cells, which 
absorb water out of the earth ; the water mingles 
with the denser cell contents, and the denser 
cells adjoining act in a similar way to each other, 
passing, the sap upwards, and thus starling 
circulation of sap. ft is thus, by imbibi'ion of 
water, that we get tension of the cell membrane, 
resulting in various modifications of cell and 
vessel formation in various parts of the plant. 
There is, however, another action performed 
by the film of our bladder, which we will now 
suppose to contain a stained substance (of 
different density to the surrounding water). Not 
only will the water be passed in bv endosmose, 
but a portion of the bladder contents will pass 
outwards by exosmose. The sap passes upwards 
by the central parts of the plant until every 
growing part is bathed by it as completely as our 
own flesh cells are momentarily supplied by the 
circulatory system of the blood. The green 
colour contained in the leaves and many stems of 
all plants is chlorophyll, a chemical substance 
which can only be secreted by the cells in the 
presence of iron and light. Openings between 
cells (stomal a) permit the passage of the 
atmosphere amongst the cells, and as the at- 
mosphere contains a varying percentage of 
carbonic acid (carbon dioxide 0 0 2), a peculiar 
action takes place immediately this gas comes 
into contact with the grains of chlorophyll 
moving about in the cell-sap, i.e . , the carbon is 
seized and split from the carbon dioxide, ihe 
ox ygen is set free, to again refreshen the air. 
The carbon particle grows gradually into starch 
grains by additional secretion, but as these are 
insoluble in water alone, they remain fast 
prisoners in the cell, waiting to be acted upon in 
another way (be it remembered that the move- 
ment of water holding various substances, mineral 
and otherwise, is a constant necessity of life and 
crowth) by metastasis ; that is, certain chemical 
constituents of the sap (mineral, alkaline, or 
acid substances held in solution along with 
alkaloids and other active principles), amongst 
other wonderful properties, posse-ses one of con- 
verting starch into sugar. It is thus dissolved 
and carried about into various parts by the exos- 
moiic action already described, to growing points 
particularly, and by consequence to the flowers. 
We have thus a perfumed nectar in the sap of 
a comparatively stiff, slugeish consistency and 
movement, by reason of its distance from its 
water supply and the amount of water lost by 
evaporation through the stomata (cell-mouth). 
If we cut in two. sharply, the stem of a juicy 
plant, we rupture the cells, when, the extremes 
being relieved, the unimprisoned sap is observ- 
able, and this is in greater quantity nearer the 
centre of the plant. On the other hand, if we 
cat a strip of bark off the round of a young tree, 
we shall notice the flow of sap greater on the 
upper portion of the remaining bark than on 
that below. We deduce from this that the cir- 
culation of the sap is (crude, weak, and fluid) up 
the centre, but down the outermost parts of the 
plant, perfected and rich in preparations ready 
to be stored in fruits (seeds), tubers, &c., and for 
the formation of new wood. There is, then, an 
outward movement of perfumed sap, rich in 
sugar, and this mu=t necessarily pass into and 
through the arrangements of superficial cells 
known as nectaries. Linneus erroneously called 
every gland-like structure a nectary, if it seemed 
not to be an integral part of the general organs 
of the flower, and De Candolle* throws much 
light on the whole subject when he informs us 
‘ that in regular flowers the nectaries may be 
found placed in a symmetrical manner and, 
not finding this the case in irregular flowers, he 
pertinently asks, ‘ Is it the presence of these 
irregularly placed nectaries which causes the 
irregularity of the flower, or is it the irregularity 
of the flower which causes that of the nectaries ?’ 
In our opinion he slowly but surely advances to 
a solution of the question, observing ‘ that when 
one sexual organ is aborted, its place is taken by 
a nectariferous gland The nectaries 
upon the inner surface of the corolla are always 
superficial, and they often cause a cavity there 
so that if, as in the case, the outer surface cells 
of the nectaries of flowers are rich in saccharine 
matters, any denser than innermost sap cells, 
the cell shape becomes contorted, having as a 
place for growth, only the surface previously 
occupied by atrophied floral organs. To make 
ourselves plain, if the stamens or petals of 
certain flowers disappear, their place being occu- 
* Vegetable Organography. 
