52 THE GARDENERS’ CHRONICLE. 
[JAN. 28, 
that it therefore would be very important to find it 
nearer home than the Islands of the Pacific, whence 
it is now imported. As it is the deposit of sea- 
fowl, he supposes that we must have an abundance of 
it on many parts of our own coast, especially in the 
Western Isles of Scotland, which are the resort of 
great flocks of sea-fowl, and in the Orkney and Shet- 
land Islands ; and he thinks the collection of it would 
be a profitable employment for the very poor inhabi- 
tants of those places. He recommends the Agricul- 
tural Society of England and the Highland Society to 
offer premiums to individuals for obtaining it, in 
order to stimulate them to exertion. 
We hardly know what to say to this proposition. 
If, indeed, the substance were really to be found in the 
places mentioned, there is no doubt that it would be 
very valuable, and afford a far more ample remune- 
ration for collecting it than the premiums of societies. 
But it is generally understood that their wet climate 
and the storms to which those islands are exposed, are 
perpetually washing the material/into the sea as fast 
as it is formed ; a circumstance which does not hap- 
pen in the dry climate whence the foreign guano is 
brought. Perhaps some one may be able to say what 
the fact really is respecting the presence of guano in 
our northern islets. 
If it should turn out that, as we suppose, it is lost as 
fast as it is produced, we are by no means sure that it 
might not be saved artificially, if a little pains were 
taken to do so. In Persia, the great manure is 
pigeons’-dung; small dove-cotes are built in the 
plains, in the form of towers, in the upper parts of 
which the birds inhabit, and in the lower of which the 
manure is collected. Access to these towers is se- 
cured by a door at their foot, which can be opened for 
the purpose of clearing out the interior ; and thus the 
extensive Melon grounds are richly manured. Could 
not means be taken to induce the sea-fowl to frequent 
particular spots, where, by means of a little contriv- 
ance of the Persian kind, the effects of rain might be 
prevented? It is to be remembered, that if this sub- 
stance could .be thus collected, it would be more 
powerful than guano ; because it would be, or might 
be, free from sand and other impurities, which greatly 
diminish the value of the imported guano. It is for 
our Scotch friends to consider how far such a project 
is feasible. 
ENTOMOLOGY.—No. XXXIX. 
OAK-SPANGLES SiLK-BUTTON-GALLS. — There 
are several different kinds of these singular and pretty 
objects which are formed upon the Oak-leaves. In some 
seasons they are exceedingly abundant, as in the autumns 
of 1840 and 1841, and at other times it is difficult to find 
any of them ; such was the case, generally speaking, last 
year. A casual observer might mistake the brown globose 
Button-galls (fig. 2) for the eggs of a large moth (espe- 
cially of a Lasiocampa), the rosy spangles (7) looking 
like the same expanded; and not a few persons have 
supposed them to be fungi. They are, however, galls, 
formed by minute hymenopterous insects called Cyni- 
iden. 
These galls are attached to the under-side of the Oak- 
leaves by a’short pedicle, as represented in fig. 5; and 
the same is shown in the centre of fig. 4, which is 
the under-side of one of the globular spangles magnified, 
fig. 3 being the upper-side. These galls are produced 
upon the under-side of the leaves, and generally on the 
south side of the tree. After the succession of heavy 
showers we had in September and October, 1841, I found 
the Oak-leaves covered with spangles in Suffolk, when 
they were larger than I had ever before observed them ; 
this induced me to examine some carefully, and on open- 
ing one I found a live shining fat maggot (fig. 6), with a 
bright yellow patch on its back, curled up and lying in a 
small cavity close to the pedicle of the gall. I opened 
several others with similar success, but could not find 
any of them in the pupa state ; and although I placed the 
leaves in a pot with damp moss, which I kept until the 
following year, I could not rear them, or if I did, they 
escaped through the fine gauze which was tied over the pot. 
was, however, fully convinced that the Oak-spangles 
were the work of a Gall-fly; and upon referring to the 
«Encyclopédie Méthodique,’’ I found the following 
short description of the insect which causes these pretty 
objects. It is a true Cynips,* but it is called by the 
French naturalists Diplolepis lenticularis :—‘‘ The an- 
tenn are blackish, a little longer than the thorax ; the 
whole of the body is black and shining; the legs are 
yellow.” The Oak-spangles are equally common in 
France, and M. Danthoine says that in Provence “ they 
are sometimes so abundant that, in autumn, when any-one 
shakes the Oaks, they fall like rain; this little gall de. 
taches itself from the leaves in the month of October, and 
remains buried during winter either in the earth or in the 
snow. Each lentil (the appellation by which he distin- 
guishes the little gall) contains rarely more than one 
larva, which comes forth a perfect insect towards the first 
fine days of spring.” 
These spangles, ox buttons, are beautiful objects when 
examined under a lens, being covered with fine fibres 
shining like silk, and varying from a greenish to a brown 
colour, with a pit, or deep circular impression on the 
crown. The other galls, which often accompany them, 
are larger, flatter, an mething like a saucer or a 
* Curtis’s Guide, Gen. 564, ii, 29 3, 
depressed Chinese hat, generally of a crimson colour, the 
outer margin a little reflexed, and the centre slightly 
elevated ; these likewise arrive at their full size in October 
and November; but in July they are very minute; at 
that time the centre is ochreous, and the ring deep red 
and velvety. I have also detected in the thickened central 
part of these a gelatinous maggot, but it is generally en- 
tirely dried up. can find no account of the species of 
Cynips which infest these galls, and am therefore unable 
at present to describe it, or to give it a name. 
I have observed a third variety of gall, in November, 
upon the Oak-leaves, which was more fleshy, and larger 
than usual : some were green and others brown ; they were 
the shape of a deep cup ; the top was open, with a minute 
tubercle in the centre. These also contained minute 
maggots, which I was unable to rear. In June, 1841, a 
fourth variety of gall was sent to me from the same Oak- 
tree which had furnished a constant supply of the Oak- 
spangles : some of the leaves exhibited as many as three 
of the galls, but most of them only one; they were 
variously placed, projected but slightly from the surface, 
and differed from all the foregoing in being equally visible 
on both sides. Upon examining the under-side of the 
leaf, the galls appeared to form a circular leathery spot, 
of a dull ochreous colour, surrounded by a thickened 
green ring, about a line in diameter; this ring was 
wrinkled, and the colour of the leaf; on the upper-side 
the spot was similar, with the addition of a little tubercle 
in the centre; and there was sometimes a conspicuous 
hole, from whence the perfect insect had escaped. 
opening one which, by holding the leaf up to the light, I 
saw contained some opaque object, I detected a shining 
piceous Cynips, with long brown antenne, a little clavate ; 
the legs were ochreous and the nervures of the wings 
deeply coloured ; by its side I saw a parasitic maggot of 
a grey colour, which had seized the Cynips, and, to my 
great annoyance, soon ate out the body, and mutilated 
the other parts. If this species be not described, I pro- 
pose calling it Cynips Quercus tiare, from the resem- 
blance of the gall to a turban.— Ruricola. 
5 
ON MANURING WITH GREEN CROPS.—No. VII. 
(By Prorzssor CHARLES SPRENGEL. Translated from 
the German. 
(Continued from page 36.) 
Ir cannot be doubted that many plants, not yet used, 
will yield good green manure, because they combine all 
essential properties in a high degree. The following are 
some with which I have made successful experiments. | 
1. Tansy (Tanacetum vulgare).—This plant, which is 
common in a wild state, and on account of its pungent 
smell and taste (owing to some ethereal oil) is not eaten 
by cattle, has hitherto been only used medicinally. If it 
is only used as a green manure, its not being relished by 
cattle is of no consequence, and is a case similar to that 
of the Lupine. The qualities which recommend Tansy are 
of much importance, viz., its roots reach 2 to 3 feet in the 
soil, and thereby bring to the surface important mineral 
substances, suchas potash, sulphuric acid, phosphoric acid, 
ete. Itis a perennial, and does not suffer from drought, wet, 
or cold, is never attacked by vermin, grows from the 
earliest spring, and yields a great mass of herbage, v!2-s 
29,000 to 30,000 Ibs. per Magdeburg acre; whilst Lupine, 
under the most favourable circumstances, will not yield 
more than 16,000 Ibs. I have not yet analysed the Tansy, 
and am, therefore, unable to state with accuracy how 
much manuring substances are added to the soil by 1000 lbs.; 
but some comparative experiments gave such a favourable 
result, that I may say that Tansy is in no way inferior to 
Lupines. At the end of May, 1837, I carted the first cut 
of Tansy on a small piece of ground, which was of the 
same size as that on which the Tansy had been grown; I 
ploughed it in five inches deep, and 8 days afterwards 
sowed Barley, which, from the first to the last, grew a8 
luxuriantly as if it had been manured with dung; nay, it 
might be even distinguished by every one from an adja- 
cent piece of Barley, which had been dressed with dung. 
In 1838, I sowed both plots with Oats; and here also 
that manured with Tansy stood much better than where 
none has been applied. ; 
If we then remember that one acre of Tansy yields 
manure for at least two acres of other Jand, that it is a 
plant most easy of propagation, as it seeds by itself, and 
even becomes a weed; that on proper soils it will grow 
for 10 years most luxuriantly, and that during that time 
it does not occasion any expense of labour or outlay for 
seed, it will be obvious that it is worth while trying expe- 
riments on a large scale with this plant. If they be suc- 
cessful (as I have no reason to doubt), 200 acres of bad 
land would not only be improved by 50 acres of Tansy, but 
also kept in such heart, that a dressing with Tansy would 
only be required every secondyear. ‘The only objection 
to this sort of green manure is, that it cannot be ploughed 
in on the spot where it is grown, but must be conveyed to 
the field. Although our native Tansy is a valuable green 
manure, yet the Tanacetum boreale, a native of Siberia, 
seems to be still better, as it attains the height of 7 or 8 
feet, whilst ours grows only 4 or 5 feet. 
2, Mugwort (Artemisia vulgaris).—This plant, which 
grows wild near roads and hedges, might be used adyan- 
tageously as a green manure, as its roots reach 3 to 4 feet 
in the subsoil, and thus bring substances to the surface 
(especially a large amount of potash), which are valuable 
fertilizers. It yields, even on poor loamy soils, as consi- 
derable a mass of herbage as the Lupine, as it can be mown 
twice a year; it lasts several years, is not attacked by ver- 
min, nor injured by weather, and it grows from the earliest 
to the latest part of the year. Still, Mug-wort, like Tansy, 
requires for its success a subsoil which contains (at least 
in some degree) all the substances required for vegetation, 
such as potash, common salt, lime, gypsum, and the phos- 
phates. When either of these plants goes off, it is evi- 
dent that the subsoil is exhausted, at least for the present, 
and they are then to be sown on other fields. I have not 
made any experiments to show how crops will grow after 
the green herbage of Mugwort has been ploughed in, still 
analogy leads me to suppose that its effects will be the 
same as those of Tansy. Perhaps it would be best to 
sow Mugwort and Tansy together, as both are often grow- 
ing so in their wild state. This culture is at any rate 
very useful, as mineral substances are thus obtained at a 
cheap rate; which, although amongst the indispensable 
nourishment of crops, cannot be applied in large quan- 
tities on account of their high price ; for instance, potash, 
common salt, phosphate of lime, and gypsum. No doubt, 
besides Tansy and Mugwort, several other wild plants 
may be used for the same purpose, the roots of which 
reach deep in the soil; for instance, Mullein (Verbascum) 
for dry sandy soils, which yields a great muss of herbage, 
and is very hardy; whilst some species of Cow Parsnep 
(Heracleum), would be more adapted for clayey soils. 
& (To be continued.) 
GARDEN EXHIBITIONS OF THE HORTICUL- 
TURAL SOCIETY OF LONDON. 
Wirn many of the Exhibitors and Friends of the Horti- 
cultural Society, I must congratulate the Prize Committee 
upon the important and useful alterations which they have 
introduced to the circular which has appeared amongst 
your advertisements. There is one thing, however, which 
IT am anxious to bring under their notice ; and I cannot 
do it better than by asking you to print the suggestion in 
the Gardeners’ Chronicle. 
‘You are aware that the exhibitions are Jess interesting 
than they might be, owing to the difficulty which is felt 
by visitors in getting acquainted with the names of the 
plants. I have frequently heard them making anxious 
inquiries of those who were supposed to be Gardeners or 
Exhibitors, and in many instances getting names which 
were either erroneous, or garbled and unintelligible. Last 
year it was reported that this defect was to be remedied, by 
the Society’s officers putting correct names to all the 
specimens ; but as this was not done, I suppose it was 
found impossible, for want of time. I would therefore 
propose that the plants should be named by the Exhibitors 
themselves, and in order to encourage them the Society 
might offer a Banksian Medal, or Certificate, for the best- 
named collections. Florists’ flowers are generally named. 
by the Exhibitors, and single specimens of ornamental 
plants have their names written upon the entry cards by 
the Clerks at the Garden; so that it is only the 
“‘Collections’’ about which there is any difficulty, and for 
which rewards would have to be offered. 
Suppose, then, that a Banksian Medal was offered for 
the best-named collection of 40 stove and ‘greenhouse 
plants ; certificates for the best ed smaller collecti 
and for Heaths and Azdleas. The names would have to 
be legibly written’ and correctly spelt, as well as placed 
upon the plants in situations where they would be easily 
read by the visitors. I have little doubt that by these 
means the visitors would be more interested than they can 
be by the sight of a splendid flower without a name ; for, 
how much soever they may admire it, they have no means 
of asking it from a Nurseryman, or of making him com- 
prehend what it is they wish to add to their collection. 
And I also think that a prize of this kind would not only 
be highly honourable to those Gardeners who might be 
successful competitors, but it would have a tendency to 
improve them in the art of writing and spelling botanical 
names.— Criticus. 
BEES. 
Tr there is anything more calculated than another to 
induce man to undertake a task, it is the appeal of a mem- 
ber of the fair sex for assistance when in distress. I have 
written many thousands of pages for the press, but never 
two lines about Bees. Although very fond of Bees, I have 
never yet written anything concerning them ; I have now, 
however, out of sympathy to a ‘‘ Despairing Bee-keeper,”” 
drawn up the following account of my experience with 
these insects during the last season only, as my avocations 
have previously prevented me from keeping Bees. 
In the month of June last, I purchased a swarm of 
Bees, which had been secured in a common straw hive, 
and the season being favourable, they appeared to be active 
and industrious on every occasion when the weather per- 
mitted them to go abroad. rom the quantity of pollen 
