192 
AMERICAN AGRICULTURIST 
[Mat, 
The White Moulds on Plants. 
A number of our cultivated and other plants are 
■often attacked by members of a small group of 
Fungi, which, from the prevailing color of the 
blotches and spots they produce, are commonly 
spoken of as the White Moulds. The mustards are 
especially subject to these moulds, their stems (a 
portion of one is shown in fig. 1) fre¬ 
quently being almost entirely cover¬ 
ed with the white spots, which have 
been likened to streaks of white¬ 
wash, and not without good reason. 
The Cabbage,Cauliflower, Shepherds’ 
Purse, and a number of other plants 
belonging to the Mustard Family, 
are subject to these pests. One spe¬ 
cies of the White Moulds is common 
on the Salsify, or “Oyster Plant,” 
and in some localities “it is so 
abundant as to excite fears that the 
crop might be destroyed. ” Figure 2 
shows an enlarged view of one of the 
spots of figure 1. It is seen that the 
epidermis, or skin of the mustard 
Fig-1. stem , is ruptured and forced back by 
a mass of white-colored substance, which arises 
from the interior. This substance consists of a 
vast multitude of spores which are white and close¬ 
ly packed together. A cross-section of one of these 
small spots from a 
leaf, is shown in fig¬ 
ure 3, from which a 
clear idea of the na¬ 
ture of the mould 
may be gained. The 
skin of the leaf is 
shown as ruptured 
and turned back—the 
substance of the leaf 
below is seen to con¬ 
sist of oval cells 
which are shaded or 
■dotted; those at the 
lower portion being 
regular in their ar¬ 
rangement by the side 
of each other. The 
fungus itself consists of minute threads, which may 
be seen passing between the leaf-cells and ending 
at the point of rupture, in rows of nearly spherical 
bodies, which extend upwards and are exposed to 
the open air. Two of the rows of spores are shown 
still more highly magnified at the right of figure 3, 
with the attachment to the thread at the base, 
some new rows of spores are beginning to be 
formed. The slender threads which pass through 
the substance of the mustard, or cabbage plant, act 
as roots for the purpose of taking up nourishment, 
and it is only after these threads, or filaments, be¬ 
come numerous and well established, that the 
fungus turns its attention to the production of 
spores. In this respect fungi, are like all other 
plants, first they accumnlate a stock of nourish¬ 
ment and then devote it, or a large portion, to the 
WHITE SPOT MAGNIFIED. 
F^g- 3.—CROSS-SECTION OF MOULD SPOT. Fig. 4. 
propagation of the kind. The white spores, which 
are formed in such large quantities, are for the 
rapid increase of the mould ; and they are carried 
by wind, rain, etc., to some new place on the same 
or another plant, where they germinate and grow, 
and produce a new spot in the course of a few days, 
thus spreading the disease with great rapidity. Be¬ 
sides the spores just described, which we have seen 
«re produced in rows upon protruding filaments, 
and are for immediate growth, there is another kind 
which is formed by a slow process by the uuion of 
filaments down in the substance of the plant upon 
which the fungus is growing. This second kind of 
spore is much larger, provided with a thick, firm 
coat of a dark color, which is variously marked upon 
the surface. A considerable portion of the growing 
season is required for the perfection of 6pores of 
Fig. 5.— WINTER SPORES AND THEIR MOTILE SPORES. 
this kiDd, and they can be found in autumn always 
within the substance of the plants. They do not 
germinate at once, but remain dormant through the 
winter, and grow the following spring. The ger¬ 
mination of these winter spores, as they may be 
called, is peculiar. The contents divide up into a 
large number, sometimes as many as a hundred, 
small bodies, each of which then grows and pro¬ 
duces a separate plant. Figure 5 shows one of 
these winter spores, also one producing a multitude 
of small bodies, each of which is provided with 
two minute hair-like threads, and capable of motion. 
Oue of these little bodies—motile spore—is shown 
greatly magnified near the center of the engraving. 
Up to the present time the injurious effects which 
have resulted from the White Moulds have been 
small as compared with those from many other 
fungi. From the general similarity of the members 
of the group in hand to the Grape Mildew, the 
treatment should be the 6ame, namely : the use of 
Flowers of Sulphur, dusting it freely upon the 
plants so soon as there are any signs of disease. 
A word can be said in favor of the White Moulds, 
in that one species is very fond of the common 
Purslain or “ Pussley,” and often attacks it so 
vigorously as to endanger its life. For this no one 
will complain. Another member is a lover of the 
“pigweeds,” and helps to keep them in check. 
If we could induce all fungi to grow only upon 
our weeds it would be a strong point gained. 
The Great Enemy to Grape Culture- 
Phylloxera. 
Since the first discoveries concerning Phylloxera, 
we have through one cause and another said but 
little about it. Indeed, since we had an article on 
the subject a vast number have taken up grape- 
growing, multitudes of new readers have come to 
our pages, and it seems necessary to give a brief 
account of it. Phylloxera is a plant-louse, the name, 
which stands for a genus of these insects, is de¬ 
rived from Greek words, meaning a leaf, and 
parched, from the scorched appearance that oak- 
leaves assumed from the attacks of another and an 
earlier known species. The full name of the one 
in question, that which preys upon the grape, is 
Phylloxera vastatriz. It is an American insect, and 
was a cause of serious losses to our grape-growers 
long before its existence was known or even sus¬ 
pected, and passing to Europe completely devasta¬ 
ted the vineyards of some localities, and where 
wine-making is an important industry, caused losses 
only to be estimated by millions of dollars. Those 
familiar with grape-vines must have noticed—espe¬ 
cially upon the Clinton—leaves studded with small 
warty looking galls, as in fig. 1, which sometimes pre¬ 
sent a very pretty appearance. Some seasons these 
are very abundant, and again rare ; these, if cut 
open and examined with a magnifier, will be found 
to contain an orange-colored insect and her eggs. 
Figure 2 represents one of these galls thus divided, 
the cross line giving the real size. This is one form 
or type of the insect, which lives only upon the 
leaves, and does comparatively little damage. An¬ 
other type of the insect inhabits only the root of 
the grape-vine, and as this is the most important 
from the injury it is capable of inflicting, we will 
not notice the other any further at present, beyond 
saying that it is called the Grape-Gall-Louse or 
gallicola-iorm of Phylloxera. A vine is observed to 
make a poor growth, the next year the growth is 
still less vigorous, the leaves turn yellow, and that 
year or next the vine dies outright. If the vine be 
dug up, it will be found to have no fibrous roots, 
and after its death it is very likely that no cause of 
the trouble can be found. If, when the symptoms 
of failing first appear, the vine be dug up and its 
roots examined, they will be found to present the 
appearance shown in figure 3, and a magnifier will 
allow the cause of the trouble to be plainly seen. 
In figure 3, a small fibrous root, one of the rootlets, 
by which the plant feeds, is shown at a. Upon the 
portions of the larger roots, marked d, d, d, great 
multitudes of minute root-lice will be found, and 
elsewhere on the root-fibres; these when young 
and tender are punctured by the insects which suck 
away at their juices, the results of their injuries 
being seen in the swellings and knots formed upon 
the root-fibres, as shown at b. After they have ex¬ 
hausted one, they go to others, and this rootlet 
soon begins to decay, as shown at c, and before 
long the whole 
root - system of 
the vine is com¬ 
pletely destroy¬ 
ed, and the vine 
of course dies. 
This being the 
form of the in¬ 
jury, let ns brief¬ 
ly describe the 
insect which 
causes it. Like 
many related in¬ 
sects, the Phyl¬ 
loxera has its 
winged and its 
wingless forms, 
and its females 
are capable of 
reproduction for 
several genera¬ 
tions without 
the presence of 
males. The insect passes the winter in the dor¬ 
mant state upon the roots of the vine, as larva, 
which is much like the root in color; when the 
growth of the vine starts in spring, these rapidly 
reach the mature wingless state, and commence 
laying eggs. In figure 4 is given a, the back, and 
b, the side view of these wingless females, magni¬ 
fied, the real size being shown at the left hand of 
b. These eggs hatch and produce other egg-laying 
females, and five or 6ix generations of them follow 
on, the insect thus multiplying rapidly and preying 
upon the growing root-fibres. About midsummer, 
some females with wings are produced, and these 
make their way to the surface, and fly away to found 
new colonies, and this continues, the production of 
winged females, until the growth of the vine 
ceases in the fall. A view of a winged female is 
shown at figure 5, of course greatly magnified. 
These winged females carry the 
-I trouble from vineyard to vineyard, 
and it is believed the wingless 
ones make their way over the sur¬ 
face and through crevices from 
vine to vine. There is much 
that is interesting in the history 
' of the insect, such as the pro¬ 
duction of both sexes after several generations, 
which start the race anew for several continuous 
generations of egg-laying females, and that the 
root-lice may produce the gall-lice upon the leaves, 
but we can not occupy space with these. The point 
with the grape-grower is, to know the disease; what 
causes it, and the remedy. Here, of remedy proper, 
there is none. Various applications have been 
suggested, but they are impracticable. The root- 
louse attacks all forms of the European vine ( Vitis 
mnifera), and is sadly destructive to it, the climate 
in many European wine countries being especially 
favorable to the development of the insect The 
Fig. 1.—THE LEAF GALLS. 
