of flowers in each ball is, in our common species, on 
1843.] 
THE GARDENERS CHRONICLE. 
627 
R. LHOTSKY, of the University of Saxe-Weimar, 
~ continues to translate, extract, or review Works or Me- 
moirs, on Natural History, Botany, Geology, &c. written in Ger- 
man, French, Italian, or Latin. Charge, for translating an average 
sheet of text, 2. 2s. etters, addressed to Mr, Pamplin, Botani- 
cal Bookseller, }rith-street, Soho, will be duly attended to. 
Ehe Gardeners’ Chronicle. 
SATURDAY, SEPTEMBER 9, 1848. 
MEETINGS FOR THE TWO FOLLOWING WEEKS. 
Wednesday, September 13 Tottenham and Edmonton 1 7 at 
Tuesday, September 19 Horticultural... + 3 rem 
Country Suows.—September 12. Berienerche Soo., Cornwall. 
~ — MM. . Kingston. 
™ - — 15 : . South Spilsby, 
\. — 1 . . Hoddesdon Cottagers, 
Prorrssor Hunstow last week called attention to 
the silent but dangerous progress that is making 
anew Agricultural pest, the Clover Dodder, which 
threatens to destroy the Clover crop altogether in 
some places. We have been favoured with a commu- 
nication, which will be found in another column, from 
Sir James M‘Adam upon the same subject ; and we 
understand that the evil is beginning to cause serious 
alarm among Agriculturists. 
There can be no effectual means of opposing the 
inroads of this new enemy, without knowing what we 
have to oppose. It may therefore be as well at once 
to explain its habits, and to offer suggestions for its 
eradication: 
The Dodders are a singular race of true parasites, 
inhabiting all the temperate and warmer parts of the 
globe, distinguished by Botanists into numerous 
species, but all having the same manner of growth and 
multiplication. They are leafless annual plants, allied 
to the Bindweeds, and, like them, strangling whatever 
they lay hold of. ‘Their flowers, which are small, 
appear in balls on the stems, speedily form fruit, and 
end in producing each four seeds, about the size of a 
grain of Mustard, within which is coiled up an embryo 
plant, looking like a miniature snake. As the number 
> 
Se 
an average, about fifteen, it follows that every ball 
will furnish about sixty young plants—whence the 
rapid spread of such pests may be easily understood. 
‘As soon as the seed of the Dodder is ripe, it falls to 
the ground, and usually seems to lie dormant till the 
succeeding year; sometimes, however, it is said to 
germinate immediately. When the spring returns, 
the embryo sends one end down into the earth to form 
a root, and with the other it rises upwards, like a small 
white thread or worm. At this time it is not a para- 
site, but seems to derive its food from the soil, like 
ordinary plants. It cannot, however, do so long, but 
withers and perishes, unless it touches some Givin 
branch or stem. If it succeed in doing so, it imme- 
diately seizes the live stem by means of a sucker, 
which is protruded from the point of contact; ahd 
then, twining from left to right, and forming mare 
suckers as it twines, it establishes itself on its victim, 
and ceases to have any further connexion with the 
soil. From that time forward it isa true parasite, 
feeding on the juices of the plant it has seized upon. 
fter making a few turns round the branch, ang 
securing itself firmly in its new position, it again 
lengthens, and catches hold of some other branch, 
when more suckers are protruded; and thus it goes 
on—branching, and twining, and sucking, and branch- 
ing again—until it forms that appearance which Prof, 
Henslow well describes as resembling “fine, closely- 
tangled, wet catgut.” Now the Dodder has a new and 
independent seat of life wherever it has twined round 
a branch ; and as it is incessantly twining and sepa- 
Yating, and twining again, a single plant is speedily in 
the condition of a polype—so that if it be cut into a 
will be) the Dodder is allowed to form its seed : for, 
they will fall on the ground, lie hid in the crevices, 
and reappear with the next crop,—when all the labour 
will have to be done over again. 
Wuen the ground to be drained is of small extent 
—as a garden or small paddock—the spade is the best 
instrument to begin the work with. The main drain 
having been dug in the lowest part of the ground, with 
a proper fall into some river or diteh, the conductors 
as parallel as the ground will allow, and the tiles, with 
or without goles, laid in firmly and evenly, and covered 
as we explained before, the collectors are now to be 
dug: these will be from 24 to 30 inches deep, with a 
small declivity towards the conductors. ‘The water 
must run very slowly, and almost continually, in 
these; for if they get very dry, the moles are apt to 
work in them, and choke them: this, however, is 
not likely to happen if the drains are cut in the tough 
solid clay. 
The first thing is to dig a trench, about 18 inches 
deep, in the direction in which the collectors have been 
laid out, the bottom of which slopes very gently towards 
the conductors; this bottom must be carefully cleared 
out with the shovel, leaving a width of 9 or 10 inches 
of solid subsoil. Should the top soil be deeper, the 
trench must be deepened in proportion. This will 
require the conductors and the main drain to be 
deeper also, which should have been calculated before 
they were made. * 
In this solid clay bottom a very narrow channel, 
10 inches deep, is dug, with a spade only 3 inches 
wide at the insertion of the handle, and 14 or 2 inches 
at the end, the length of the blade being 13 inches, 
leaving 8 inches of solid earth — 
on each side. The annexed cut 
will give a clearer idea of it. 
‘The slit which forms the channel 
for the water is 10 inches deep, 
and is cleared out by a hollow 
scoop, 2 inches wide, made of 
strong sheet-iron, steeled at the 
point, and attached to a long 
handle at an acute angle, as in 
the annexed cut: this leaves the bottom and 
sides of the channel quite smooth. When this 
collecting-drain is finished, it must 
be covered, first, with tough peat, 
if this can be got, or sods, with the 
grass downwards, or with heath 
pressed in by the feet, so as to fill 
a third of it, and a few inches of 
the trench, as is marked by the 
dotted line. If no heath is to be 
had,a rope of straw may be twisted 
and forced in: this will last a long time, and if it 
decays, the earth over it will have formed an arch, 
which will keep the drain open when the straw is 
rotten. We have seen drains thus made, which ran 
well after they had been made twenty-five years. The 
peat, sod, heath, or straw, must be well pressed in with 
the feet, so as to form a complete plug, leaving 6 inches 
clear below, for the water to run; over this, some 
| mellow earth from the surface, or small gravel, should 
be thrown in, till the trench is filled up to the bottom 
of the top soil. This should be well rammed in, in a 
dry state, and over it, to fill up to the surface, the 
common soil may be used. If the surface is in grass, 
the sods may be laid back from the place out of which 
they were dug, allowing something for the sinking 
of the earth. . 
Yn a kitchen garden all the drains must lie deeper, 
to allow for the usual hing. There the collect 
may be 3 feet deep, and the conductors and main drain 
3 feet 6 inches and 4 feet respectively. ‘This method, 
although it is somewhat expensive, will soon be found 
frable, b i 
thousand pieces, each piece will i ately go on 
growing, as if nothing had happened to it. Tearihg 
the Dodder to pieces, then, so far from extirpating it, 
only multiplies the mischief, instead of arresting it. 
This short statement will show thatit is a formidable 
enemy that bas been thus unfortunately introduced to 
our fields ; and, as_these things are not very nice in 
their food, it isnot impossible that the Clover Dodder 
May next take a fancy to our Wheat fields, unless we 
Can speedily put an end to its presence. It is of little 
Use to cut it in pieces,—it is of no use whatever to do 
So, if the fragments are left where they can catch hold 
of anything else. : 
As it is only an annual, it would be killed if we 
could prevent its flowering ; but that is difficult, 
because of its hiding itself among the lower branches 
of plants, where it cannot well be seen: and a few 
eads of flowers will soon renew it in a succeeding 
year, The right plan would be to dig up the Clover 
where the Dodder appears, 80 as to form a circle con- 
siderably beyond the patch apparently formed by it, 
and then to burn it in heaps; or, in cases where the 
entire field is infected by it, to sacrifice the whole 
Crop, and burn it. This may appear @ violent remedy, 
but it is the only one likely to be effectual; and even 
this will fail, if (which is not yet the case, but soon 
p the imy of the soil and the in- 
crease of the produce. 
But if the land to be drained is extensive—say 
fields of from ten to twelve acres—and the soil at top is 
poor and shallow, the expense must be reduced as 
aq 
will 
the conductors. 6 
Let a plough make parallel furrows across @ b, 80 
as to have a very slight deviation from the level, say 
one inch in 10, feet, more or less. The distance of 
these furrows may be from 10 to 15 feet, according 
as the soil is more or less retentive of moisture. e 
usual width of 9 inches, with a depth of 6, will 
lo very well. On returning, the plough makes 
another furrow, leaving a small balk between it and 
the first. 
The section of the furrow will then be as 
An under, where a @ 
is the slice turned 
over b &, the two 
furrows. The 
plough next splits the balk d, taking five or six inches 
more of the soil and raising it up obliquely, against 
the sides of the first slices, right and left. Thus a 
trench is made 10 or 11 inches deep, and 18 wide. 
The section of the trench will now be somewhat as 
under, if the mould-board is of a proper concave 
snpet. aut the i 
subsoil will pro- e 
bably have been us UF ee 
reached. In this 
trench the drain- We 
ing spade is to be 
used, digging out 
a trench 9 inches - 
deep and 9 in- 
ches wide. The 
bottom will now 
be 19 inches below the surface, and the narrow spade 
and scoop finish the narrow drain, the bottom of 
which will be 27 or 28 inches—quite deep enough 
for ploughed land to allow of subsoil-ploughing with- 
out danger of interfering with the drains. For more 
minute particulars we must refer to the “ Journal 
of the Royal Agricultural Society of England,’ 
vol. iv., p- 28. It must be noted that the plough 
crosses the conductors, and that only a portion 
of the trench made by the plough is required for 
the collectors: but it would be more trouble to have 
loughed out short trenches of 20 or 25 feet in 
length than to go on from one side of the field to the 
other at once. ‘The ploughman may raise the plough 
and ease his horses when he goes over the portion 
which he knows will not be dug out; but at first, 
before he is quite aware of the plan, it will be best 
to let him plough to the same depth throughout. The 
stirring of the soil will do good, even where no drain 
is wanted, and the whole trench will be filled up by 
reversing the operation. 
Tf the subsoil is not of a uniform clay, some varia- 
tion will be required in the operations, which we will 
next touch upon. The principle, however, will be 
the same.—M. 
In our observations last week on New Zealand, is 
a typographical error which destroys the meaning of 
the paragraph in which it occurs. Speaking of the 
mode of clearing fern land we are made to say, “‘ No 
doubt the wiser course is to leave it (the fern) in the 
first instance.’ What should have been printed was 
—No doubt’ the wiser course is to burn it in the 
first instance,” as indeed is obvious from the context. 
Since we are obliged to correct this error it will be as 
well to explain why we recommended the fern to 
be burnt, since it involves a question of general 
husbandry in other countries as well as New Zealand. 
Wherever uncultivated land has been long occupied 
by a rank vegetation, of whatever nature, it is neces- 
sarily rich in what is called humus; viz., that black 
matter which results from the decay, year after year, 
of fragments of leaves and branches that fall on the 
ground ;—in other words, it is rich in carbon. To 
such land it is useless to add more carbon. If the 
vegetation that overruns it is gathered together and 
forced to decay, so as to become ordinary manure, 
and in that condition is restored to the land, that 
would be to add carbon uselessly to soil already con- 
taining it in excess ; 80 that all the time and labour 
employed in preparing and applying such manure is 
total loss. ; 
But, on the other hand, it is equally mischievous to 
carry the wild vegetation off the land, for that would 
be to incur a large expense, and at the same time to 
impoverish the land ; for this reason: all vegetation, 
of whatever kind, contains alkaline and other matter 
taken from the soil in the process of growth, and 
absolutely necessary to the health of plants. Such 
matters should never be removed, for soil rarely 
contains enough of them. Ferns yield as much as 
34 per cent. of such matter, obtained from a great 
depth beneath the surface. The question is, how to 
preserve the alkaline and other matters that are 
important, and to be rid of the carbonaceous sub- 
stances which are superfluous ; the answer is, by fire, 
which destroys all the latter, and leaves all the other 
behind in the form of ashes. 
But it is not merely the preservation here of sub- 
stances valuable, and the destruction of matter useless 
to plants as food that is accomplished by fire: Another 
most important purpose is thus served. The black 
mould of such places as the New Zealand fern land, is 
like our peat mosses, in great part very slowly con- 
vertible into vegetable food, because of its insolubility. 
