Octoter 3i, 1903. 
THE GARDENING WORLD. 
913 
day, so that we had the pleasure of seeing them late in the 
afternoon, hut in bright weather the flowers close by day, the 
variety being described as a night flowering species. It is; very 
handsome by artificial light, however, and is useful for table 
decoration. The leaves are very large, circular, and wavy at 
the edge. It has been in bloom for three months. 
More recently another open-air tank has been constructed 
and planted with a variety of subjects, which may be seen by 
reference to our supplement 'this week. The tank is heated 
from a neighbouring vinery. The most important plant on 
this occasion is Eicliomia speciosa, which produced between 
six hundred and seven hundred flower spikes last September. 
The spikes are rather short, but a good many of them may be 
seen by reference' to the illustration. The plants are entirely 
floating in the tank, and their flowering so freely is rather 
remarkable during such a cold and sunless season. In the 
tropical tanks at Eew they grow taller, but rarely flower. The 
profusion of pale blue flowers on this occasion is quite a record. 
The Canna seen at the back of the picture was Egandale, a 
variety with rich bronzy-purple foliage. On the left are some 
fine bushy specimens of Dimorphanthus, with Marvel of Peru 
flowering beside them. In this tank also are specimens of 
Nymphaea stellata Berlin variety and Nelumbium species-uni 
and N. kennesinum, but the most important plant was 
decidedly the Echornia speciosa. E. azurea is also grown at 
Gunnersbury House, but our picture was accidentally so- 
named, though we take this opportunity of correcting it to 
E. speciosa. Mr. Hudson grows all these things very success¬ 
fully. 
Lac and Lac-yielding Plants. 
hr John It. Jackson, A.L.S., ex-Ke-eper, Museum, Boyal 
Gardens, Keiw. 
The fact that one of the principal duties of the gardener is to 
get rid with all possible speed of every kind of infesting 
insect that may attack his plants may be a sufficient reason, for 
bringing before- the readers of The Gardening World a subject 
which bears entirely against such a destructive policy, and, as 
a consequence,' ends in the preservation of the insects and the 
destruction of the plants. At first this may seem to- be opposed 
to- good cultivation, but where plants are cultivated for profit 
alone and not for the personal delight of the grower, it is 
natural that the side which realises the largest amount should 
receive the first consideration. 
That insects which attack plants are often of great economic 
importance and co mm ercial value is shown in that well-known, 
article, cochineal, where the species of Opuntia upon which 
the insects feed are, to the cultivator, only of consideration as 
the means of supplying food to the insects which are them¬ 
selves the resultant crop for which the plants are grown. 
In the matter- of lac-yielding plants, the case is somewhat 
different from that of cochineal, inasmuch as the plants that 
are attacked by the insects belong to various natural orders 
widely separated from each other. And, moreover, they are 
not systematically cultivated, so that the lac is gathered from 
trees growing over very wide areas. It may be interesting to- 
note that the insects producing both cochineal and lac are 
closely allied species of the same genus, the former known as 
Coccus cacti, and the latter as Coccus lacca. In the: first, case, 
when the wingless; females are- placed upon the plants of 
Opuntia, they gorge themselves with the juice and become* 
fixed, when they lose ail power of locomotion, the legs prac¬ 
tically disappearing with the increased growth of the body. 
Something similar occurs with the lac insect; thus, when the 
larvae escape from the eggs they go in search of the fresh sappy 
twigsi of one of the resinous plants which they are known to 
infest. Upon these they become attached and form a, kind of 
cocoon by excreting a resinous, substance. The plants chosen 
y the lac insect are those of a naturally resinous character, and 
though there are many which they so favour, they are, never¬ 
theless, limited when we consider the extent of the flora of 
the countries in which Coccus' lacca works, its operations being 
described as follows: The bark of the twig is penetrated by the 
proboscisi of the creature “ until it reaches the sap-wo-od ; 
fropa there it sucks its nourishment and transforms the sa,p 
into the resinous excretion-lac, which it encrusts around itself. 
As time advances further changes are visible; the body of the 
female enlarges considerably and becomes brilliantly coloured. 
The rich colour is due to the formation of a substance intended 
a,s food for the offspring. Tire eggs germinate below, and the 
larvae, eating their way through the body of the mother, make 
their escape, to repeat this- strange history.” 
After the escape of the larvae the twigs with the encrusted 
resin or lac are removed and out into lengths of from 4 in. to 
6 in., and in this form the article is known as sticklac. To 
remove the lac from the twigs, they are spread out on a floor 
and a roller drawn over them, which leaves the twigs clear 
and at the same time breaks up the resin into small pieces, but 
it is further beaten with a pestle or trodden out in water, which 
extracts the red colouring matter, the w’ashings being carefully 
Fruiting Twig of Zizyphus Jujuba. Yields Lac. 
evaporated, when the residue, after it has been formed into 
small cakes and dried, becomes the lac dye of commerce. The 
remaining resin, freed of impurities, and now in the condition 
of small granular pieces, is known in the market as seedlac. 
Shellac, which is the form most familiar in oilshops, is 
prepared as follows : The seedlac, after being thoroughly dried, 
is placed in long, narrow bags, which are then stretched over 
charcoal fires; the heat melts the lac in: the bags, and these 
being twisted or wrung in opposite directions, the melted lac 
is forced through the 1 fabric of which the hag's are made and 
falls into shallow porcelain troughs or on to- the smooth surface 
of a. Plantain leaf. In these receptacles it spreads out into 
thin sheets or flakes. If the lac, after melting, is allowed to 
drop from the bags in large pieces, it is known as bulton-lac, 
or sheet-lac if in large flat sheets, or thread-lac if in a fine 
tlmead or hair-likei condition, for lac is known in commerce 
under very many forms as well as qualities, the latter de¬ 
pendent chiefly upon the plants from which it is obtained, the 
bast, quality being that from the Kusum tree (Schleichera 
trijuga), which is the most important source of lac in India, 
