August 1, 1898.] Sappleinent to the ''Tropical Arjricaliurisf:'' 143 
dried. It con tlieti be used as required. In re- 
l)otting plants I simply put a little of this in the 
bottoms of the potss, oiid as soou ns the roots 
reach it, the effects can be immedifitely seen. 
Being in a dry state, there is no smell while using 
the charcoal- 1 nlso use this in a powder to the 
soil to darken and enrich the flowers of dahlias, 
petunias, roses and other flowers, and the foliage 
of all is improved by the use of thi-, combined 
with wood ashes. 
1 think it would be advisable for every one 
to preserve all the ashes they possibly can in a 
dry condition and distribute them over the roots 
of the trees in the orchard and also in the garden. 
If the soil has bten roughlj' dug, the ashes may 
be scattered on the surface each day they are col- 
lected. It wuuld not be amiss to utilize the ashes 
in this direction all the year round, since the 
trees will be benefitted thereby. They do their 
■work slowly but surely, and this 1 have proved 
by experience. 
NATURAL INCUBATION AND THE DEVELOP- 
MENT OF THE CHICK. 
This is a subject which is little understood even 
by those who make a business of poultry-keeping, 
and we therefore take over for the benefit of our 
reader?, an extract dealing with the subject from 
an article on Incubators and Incubation contiibuted 
by Mr. J. McCue to the last number of N.S.W. 
Agricultural Gazette : — 
All hens at one time possessed the natural 
desire to incubate, but a long course of selection 
by poultry breeders has eradicated it in some 
breeds, i.e., Hambrugs, Leghorns, &c., which now 
rarely have a desire to iucnbute. A hen, if left 
to itself, will prepare a shallow nest for her 
eggs, let her bo a sitter or non-sitter. The non- 
sitter will go on laying, but will seldom show the 
maternal propensities by sitting on her eggs. Tiie 
sitter, after preparing her ne.Jt, will at some 
time during t!ie laying period settle down to 
incubate her eggs, 
AVheu a hen is broody the plexus of the organ 
of incubation is developed. This consists of a 
number of arteries ramifying beneath the in- 
tegument of tiie abdomen, which form by their 
union a rich network of vessels wdiich becomes 
truly extraordinary during hatching. Through 
these arteries the worm blood is brought to the 
surface of the abdomen, nearest the eggs, bringing 
the temperature of the eggs nearly to that of 
the fowl. 
Alter the hen has become properly broody and 
prepared herself she sits on the eggs, more or less 
constantly for twenty-one days, turning and 
moving the eggs from time to time about in the 
nest, to assist the development of the chick and for 
her own comfort. Thy number of times that a hen 
leaves her nest depends on the weather, if and she 
is fed or is compelled to find her own food. If 
the weather is hot she leaves the nest more often, 
dusts and cools herself more often ; if the weather 
be verj' warm during the hist three or four days of 
th» hatch many chicks will be found dead in the 
shell. Just before the chick breaks the shell the 
eggs sweat ; after the chick comes into the world 
it at first sweats profusely — is very sensitive to 
cold at this time, and nestles close under the 
mother for warmth. 
As most poultry-breed:>rs knov/, all fertilised 
eggs liave tlie germ of life when laid, and it 
remain; in a kind of dormant state if rhe tem- 
perature is not allowed to reach 70 or 80 degrees. 
Dr. W. H. Eansom, who has investigated^with 
great care, says : " That the unfertilised ovum or 
egg continues, for a time, to undergo changes 
similixr to those which the fertilised egg undergoes ; 
but that these clianges, becoming lan^giiid and in- 
complete, are finally arrested by dtcomposicion." 
The yolk of nii egg is encased with a tliin skin 
called the vitelline membrane, viz., a transparent 
and flimsy membrane. On the upper surface of 
the yolk, and imraedialely under this membrane, 
v.'ill be found a little semi-oj) ique spot ; this is the 
germ-spot or blastoderm. During the passage of 
the egg along the oviduct of the^fowl, it is in a 
temperature of 105 to 110 degrees, and the germ 
undergoes important changes during its passage 
down the oviduct. 
From the germ of every egg a narrow passage 
runs to a small cliamber in the centre of the yolk. 
As the yolk mature.s, the ovisoc becomes thinner, 
especially around its greatest diameter. Aroutid 
this diameter, when the yolk is almost inatured, a 
belt— s^;>wt«— appears. Then fecundation takes 
place, the sac ruptures at the stigma, and the 
fertiliaed yolk, covered with a thin substance, is 
received by the funnel-shaped opening of the 
oviduct, or egg passage. On its w .y through this 
pa.s.sage, the yolk becomes enveloped in a white 
fluid— albumen. This is secreted by the mucous 
membrane of the oviduct, and is added layer by 
layer as the egg passes on. 
The albumen of the egg forms the chief nourish- 
ment of the chick, being'absorbed very fast by the 
little embryo; it also gives room to the 'fast- 
growing animal, Aibumen, being a bad conductor 
of heat and coir], guards the gorm-life in the 
hatching eggs against chills, which may occur 
when a lien leaves her nest, for food, &c. It also 
preserves the yolk and germ from sudden shocks 
or injury. Besides the ordinary albumen, there are 
two cords, or stiings, of a slightly fibrous albumen 
found ; these strings, called thechalazce, are spiral- 
shaped and f,astened to the yolk— one at the air- 
bubble end, the other to the small end of the egg. 
These tvi'o cords act ts balance-weiglits to the yolk, 
keeping the germ uppermost, wliere it can best 
receive the heat to incubate it. 
After nn egg has been incubated for a -hort time, 
the germ-spot enlarges by the development of 
small vessels, which spread until tliey almost cover 
the yolk. From the germ-spot a fl.-'sk-shaped tube 
proceeds to the centre of the yolk. During the 
growth of the embryo, many chemical and physical 
changes happen; blood-vessels appear about the 
third day in the membrane that lines the shell, 
and this being porous, admits the air necessary to 
aerate the blood. Tlie air-bublile at the larger end 
of the egg becomes larger by the evaporation of 
the water from the albumen through the pores, and 
the consequent influx of air to take its place. 
The chick, until nearly developed, is encased in 
a thin .skin, or membrane, which is broken by the 
beak of the chick on the nineteenth day. The 
chick begins to use its lungs for the fir.-t lime by 
using the air in the much enlarged air-bubble. At 
