>2 
AMERICAN AGRICULTURIST. 
[January, 
and on the other hand from the most delicate cream 
and sulphur colors up to the deepest orange. In 
many the leaves are very elegant, not only in form, 
but they are often handsomely veined and tinted. 
The catalogues of the European dealers offer about 
a hundred named varieties, and though the lists of 
our florists are not so full, they offer a good selec¬ 
tion at moderate prices. Not the least of the mer¬ 
its of the Tuberous Begonias is the ease with which 
they are raised, and if one can get seeds of a good 
strain, plants quite as fine as the named varieties 
may be produced. A pot of good, rich, light soil 
should he prepared; the very fine seeds are to be 
sprinkled over the surface, and merely pressed down 
into the soil; cover the top of the pot with a pane 
of glass, and keep in a temperature of 50° to 60°. 
When the plants are large enough to handle, pot 
them off into similar soil. Started in February, and 
well cared for, the plants will be large enough to 
turn into the open ground and flowerthesame sum¬ 
mer. They may be kept in pots to bloom in the 
greenhouse, for the decorating of which in summer 
they are especially valuable. They are essentially 
summer-bloomers, and when their bloom diminishes 
the water should be gradually withheld, the tops 
allowed to die down, and the tubers allowed to 
ripen ; these may be kept in the earth, or taken out 
and preserved in a warm place until spring, when 
they are to be potted and started into new growth. 
What is the Black Knot? 
The conspicuous excrescence often found upon 
Plum, and wild, and cultivated Cherry trees, and 
well named the Black Knot, is an old enemy to the 
fruit-grower. From its destructive nature it early 
received the attention of scientific men, and much 
has been written and said upon this subject, in 
fact, much more than was really known. Some 
have claimed that the knot was caused by insect 
stings, a form of gall, in nature like those on the 
oak, willow, etc. 
The fact that the 
knots—especially 
the old ones—fre¬ 
quently contain 
insects and their 
eggs, remains, 
etc., was accepted 
as evidence that 
such was the case. 
Though many in¬ 
vestigators have 
found a fungus 
present in the 
knot; it having 
been first de- 
scribed by 
Schweinitz, in 
1838, yet, until 
the recent, and 
thorough investi¬ 
gations made by 
Professor Farlow 
of Harvard Uni¬ 
versity, all doubt 
of fungus origin 
was not cleared 
away. The fol¬ 
lowing are his rea¬ 
sons for believing 
that the knot is 
not caused by in¬ 
sects : “ First the 
knots do not re¬ 
semble the galls 
made by any 
known insects. 
Secondly, al¬ 
though insects, or 
remains of insects are generally found in old 
knots, in most cases, no insects at all are found 
in them when young. Thirdly, the insects that 
have been found by entomologists in the knots, 
are not all of one species, but of several dif¬ 
ferent species, which are also found on trees that 
are never affected by the knot. On the other hand, 
we never have the Black Knot, without the Sphceria 
Fig. 1.—MATURE STATE. 
moibosa, [The scientific name of the fungus. Ed.].. 
and the mycelium of that fungus, is found in the 
slightly swollen stem, long before anything that 
could be called a knot, has made its appearance on 
the branch ; and furthermore, is not known to occur 
anywhere except in connection with the knots.” 
The Black Knot is most conspicuous in the win¬ 
ter season, when the trees are not covered with 
foliage, and they range in size, from half an 
Fig. 3. Fig. 4. 
inch, to a foot or so in length. The knot does 
not usually surround the branch on all sides, but 
growing from one side, often causes the branch to 
bend away from that side, or twist into an irregular 
shape. A knot, much reduced in size, is shown in 
figure 1, with its surface undulating, and more or 
less cracked. When the knot is a large one, it usu¬ 
ally kills the branch, or continues to spread up and 
down from the old knot, until death comes to the 
branch. Figure 2 shows the Knot in its early stages. 
In the spring the affected part increases rapidly in 
size—one might al most say puffs out—and the whole, 
growing larger, becomes thick and is soft; rupture 
of the bark soon follows, and the soft substance, 
coming to the surface, expands rapidly, and is soon 
coated with a characteristic greenish color. All 
this time the threads of the fungus have been in¬ 
creasing rapidly; in fact, the swollen substance is 
made up largely of these threads, and as they de¬ 
velop and become exposed by the rupture of the 
bark, multitudes of spores form on the interior fila¬ 
ments. Fgure 3 shows a thin section or slice through 
the young knot, with the exterior threads of the 
fungus, producing small spores, a, a. The same is 
seen more highly magnified in figure 4. This takes 
place about the time the cherry and plum trees are 
in flower. These spores continue to be formed, 
until midsummer, when a new development begins, 
which is for the production of the winter spores. 
As autumn approaches, the black color develops, 
the outer surface hardens, and frequently the inte¬ 
rior soft substance is destroyed by insects, and only 
a shell remains. In this crust, are small nodules, 
or protuberances, one of which is shown in figure 5. 
These nodules are pits, on the inside of which a 
multitude of small 
sacs are attached. 
Figure 6 shows two 
of these sacs, in 
each of which are 
eight spores, the 
universal number 
in this species of 
fungus. These 
spores are not ful¬ 
ly developed, until 
very late in the sea¬ 
son. The Choke 
Cherry (Primus 
Virginiana) is a 
favorite home for 
the Black Knot, as 
the neglected fence 
rows in winter 
show. Next to the 
choke cherry, in 
the severity of its 
attacks, are the 
cultivated vaijcties Fig. 6.—spore sacs. 
of cherries and 
plums. “ The Morello Cherry is more susceptible 
than any other variety, and next in order comes the 
Mazzard.” Some varieties are free from the knot. 
Remedy. —Like all troubles caused by fungi, the 
Black Knot is contagious, and is propagated by 
the millions of spores it produces, one crop of 
which is developed through the spring and summer, 
and the other in the late autumn. The knife is 
the remedy. Cut off the knots, wherever, and when¬ 
ever found, and burn them. This can best be done 
in autumn, after the leaves have fallen, and the 
knots are exposed to view. The Choke Cherry 
bushes and trees, might better be cleared away 
entirely, if situated near pear or cherry orchards. 
How the Japanese Pack Bulbs. 
-O- 
Travellers in Japan, give interesting accounts of 
the gardens of that country, and tell of the ingen- 
JAPANESE LILY-BULB CASE. 
ious appliances, such as shades made of bamboo 
strips, and greenhouses covered with paper, so pre¬ 
pared as to serve as a substitute for glass. The 
specimens that come to us, show that they are well 
advanced in the art of horticulture. We saw the 
first of the beautiful Japanese Maples that came to 
this country, and these, as well as other plants, 
showed, that in grafting, they had little to learn 
from us. We were recently at the opening of a 
case of lily bulbs, just imported, and these were 
packed in a manner that showed not only great 
care, but a knowledge of the requirements of the 
bulbs. The bulbs in question were remarkably fine 
ones, of the golden-banded lily, IMium auratum. 
Upon opening the ease, only large flattened balls of 
dried mud were to be seen. Each bulb was envel¬ 
oped by a covering of what appeared to be dried 
