THE COTTAGE GARDENER. 
June 
120 
deficient in—are tlie facts exhibited by plants in a 
state of disease. Knowledge on this subject can be 
only acquired by observation and experience; that 
is, by conversing with the things about us, by 
noticing them attentively, and by subsequent reflec¬ 
tion. Every cultivator is capable of doing this; and 
if, when he found his crops diseased, he would reflect 
and record from what soil he obtained his seed; how, 
and in what weather, it was committed to the 
ground ; its subsequent culture; the crops that pre¬ 
ceded ; the treatment of the soil; the seasons, whether 
wet or dry, or severe, through which the diseased crop 
has vegetated; with any miscellaneous observations 
that his own common sense might dictate, vegetable 
medicine would soon advance more in one year to¬ 
wards that state of reasoned knowledge that deserves 
the name of science than it has done during the last 
century. As observations multiply, the adjutant 
sciences, chemistry and botany, will contribute and 
apply their improved stores of information; and if 
few specifics for the diseases of plants are discovered, 
we are quite sure the causes of disease will be better 
ascertained; and every one is aware that to know the 
cause of an evil is the most important step towards 
its prevention. 
It is some help to a research in this interesting 
department of knowledge to understand clearly what 
disease really is, and to comprehend generally whence 
it arises. As the health of a plant is the correct 
performance of its functions, disease may be defined 
as the disturbed, or incorrect performance, of one or 
more of those functions; and the mildew which des¬ 
troys our peas; the curl that infects our potatoes; 
the ambury, or club-root, to which our turnips and 
other species of brassica are liable; and the shank¬ 
ing, or ulceration, which attacks the stalks of our 
grapes, are only a few of the most commonly 
observed instances of such disturbance. The dis¬ 
turbance in every instance arises either from one or 
more of these four causes:—1. Decline of energy in 
the plant arising from its old age. 2. From the 
attacks of parasites, whether insects or plants, which 
wound its vessels and suck from it its juices. 3. Its 
food being improper either in quantity or quality; 
and 4, being made to vegetate in an ungenial tempe¬ 
rature. 
We are much tempted to dwell at some length 
upon the various diseases arising, specially, from 
each of these causes; but we think it will be much 
more beneficial to consider, without any prefixed 
theory, each disease that may be brought to our 
notice; remembering, and begging our readers to re¬ 
member, those causes whilst dwelling over the details. 
We have been requested to give some information 
relative to the Chilling in Callages, and we shall 
do so from another work in which we stated the 
results of our researches concerning this disease. It 
is peculiar to the Brassica tribe, and is known by the 
various names of Hanbury, Anbury, Ambury , and 
Club Hoot. Fingers and Toes, a name applied to it 
in some parts, alludes to the swollen state of the 
small roots of the affected plants. 
Cabbage plants are frequently infected with ambury 
in the seed-bed, and this incipient infection appears 
in the form of a gall or wart upon the stem imme¬ 
diately in the vicinity of the roots. If this wart is 
opened, it will be found to contain a small white 
maggot, the larva of a weevil. If, the gall and its 
tenant being removed, the plant is placed again in 
the earth, unless it is again attacked, the wound 
usually heals, and the growth is little retarded. If 
the gall is left undisturbed, the maggot continues to 
feed upon the alburnum, or young woody part of the 
stem, until the period arrives for its passing into the 
pupa form, previously to which it gnaws its way out 
through the exterior bark. The disease is now almost 
beyond the power of remedies. The gall, increased 
in size, encircles the whole stem; the alburnum being 
so extensively destroyed, prevents the sap ascending, 
consequently, in dry weather, sufficient moisture is 
not supplied from the roots to counterbalance the 
transpiration of the leaves, and the diseased plant is 
very discernible among its healthy companions by 
its pallid hue and flagging foliage. The disease now 
makes rapid progress, the swelling continues to in¬ 
crease, for the vessels of the alburnum and the bark 
continue to afford their juices faster than they can 
be conveyed away; moisture and air are admitted to 
the interior of the excrescence, through the perfora¬ 
tion made by the maggot; the wounded vessels 
ulcerate, and putrefaction and death supervene. The 
tumour usually attains the size of a large hen’s egg, 
has a rugged, discharging, and even mouldy surface, 
smelling offensively. The fibrous roots, besides 
being generally thickened, are distorted and mon¬ 
strous from swellings, which appear throughout their 
length, apparently arising from an effort of nature 
to form receptacles for the sap, deprived as it is of 
its natural digestion in the leaves. These swellings 
do not seem to arise immediately from the attacks of 
the weevil, for we have never observed them contain¬ 
ing its larva. 
This disease when it attacks the turnip is a large 
excrescence appearing below the bulb, growing to the 
size of both hands, becoming putrid and smelling 
very offensively. 
These distortions manifest themselves very early 
in the turnip’s growth, even before the rough leaf is 
much developed. Observation seems to have ascer¬ 
tained that if the bulbs have attained the size of a 
walnut unaffected, they do not subsequently become 
diseased. The maggot found in the turnip ambury 
is the larva of a weevil called Curculio gdeurostigma. 
Marsh am describes the parent as of a dusky black 
colour, with the breast spotted with white, and the 
length of the body one line and two-thirds. 
