July 20, 1882. ] 
JOURNAL OF HORTICULTURE AND COTTAGE 
GARDENER. 
63 
effect is soon lost by its being washed away. Hand-picking 
every night was the only way to preserve the plants, and now 
they are not looking nearly as well as they ought to do at this 
advanced period of the year. The result of our labours this 
season have certainly not equalled the favourable expectations 
that were at one time entertained.— Amateuk, Cirencester. 
SILKWORMS AND SILKWORM REARING.—12. 
(Continued from page 540, last volume.') 
To what has been already stated concerning the methods of 
rearing the common silkworm (Bombyx Mori) I wish to add, 
by way of supplement, an extract from some observations upon 
the subject appearing in the “Entomologist” of June last. 
These interesting remarks are penned by Miss E. A. Ormerod, 
a lady who has distinguished herself in the direction of economic 
entomology especially, and who is now appointed honorary con¬ 
sulting entomologist to the Royal Agricultural Society. It seems 
that about ten years ago this lady made some experiments in 
rearing the Mulberry worm, a parcel of larvae received at the 
beginning of June being divided into three companies or parties. 
All were fed similarly upon Mulberry sprays, in length from 
12 to 18 inches or so, which were placed in pots and boxes of 
earth, and which were found generally to retain their freshness 
until the leaves were almost stripped. The surface earth of the 
pots, upon which the excretions of the silkworms fell, was occa¬ 
sionally removed. Little handling was requisite, and they had 
the advantage of plenty of air with natural exercise on the twigs. 
One of the parties was reared in a succession vinery, where the 
air was kept damp, and the temperature was genial but not high, 
varying somewhat when the heat of the sun was 
admitted. A second party was placed in a room of 
equable temperature (about 62°), cold air being ex¬ 
cluded at night. To the third was given a home in a 
garden loft, the windows of which were open at all 
times, and where occasionally the thermometer fell 
below 50°. There was no great mortality amongst 
any group out of the three, but the worms kept in the 
vinery always appeared to be more active and flourish¬ 
ing than their brethren of the room or loft; also they 
made more rapid progress, and all their cocoons were 
spun before the tardy worms in the loft had completed 
their growth. 
In estimating the value of this experiment, how¬ 
ever, it must be remembered that these silkworms 
when so distributed were not newly hatched. As they 
are stated to have been from half to three-quarters 
of an inch in length they were probably a fortnight 
old. Had worms just out of the egg been placed in 
such a loft as is described it is likely many would 
have died. The vinery, again, during the very juve¬ 
nile stage, might have had too forcing an effect, and 
obviously the feeding upon branches of Mulberry 
inserted in pots could only be carried out upon a small scale, 
whatever advantages it might have. These experiments quite 
confirm what has been previously advanced in reference to the 
need of scrupulous cleanliness and ventilation ; it is evident, 
though, that silkworms will live and produce satisfactory co¬ 
coons in an atmosphere which varies greatly in temperature. 
Nearly allied to Bombyx or Attacus Cynthia, described in our 
last article, and a species having its habitat in several districts of 
Northern Asia, is the A. Ricini, an Indian species, rather less in 
size. Bengal is the province which has supplied most of the 
examples of this insect which have been sent to Europe. As the 
name implies, the food of the caterpillar or worm is the Castor- 
oil Plant—one or more species of Ricinus. We might infer, 
perhaps, from this fact that the leaves being somewhat unctuous, 
silk yielded by the cocoons of A. Ricini would be rich and glossy. 
It does not seem, however, to have any particular excellence, 
while the cocoons present some trouble in the winding. Since 
one Castor-oil Plant can be easily cultivated in such a climate as 
is that ef Southern France, several attempts have been made to 
induce farmers there to grow crops of it, because' the seeds 
would be marketable on account of their oil. But as this 
silkworm does not promise much the enterprise is unlikely to 
be followed up, and it is a serious drawback that the species of 
Ricinus in question is only annual in Europe. 
A well-known article of Indian produce is the particular kind 
of silk called Tussur or Tussore silk, of somewhat coarse texture, 
yielded by the silkworm of an allied species, Attacus Mylitta, also 
named “ Paphia ” in some books, the latter being rather mis¬ 
leading. One or two of our British experimenters have been 
anxious to get this species encouraged in these islands, on the 
supposition that by a little management the worms would thrive 
well enough without shelter from the effects of our changeable 
climate. The silk can be wound off, although it is more usually 
reeled, and the cocoons exhibit much variety in size and colour ; 
though usually grey of some shade, they are also white or yellow 
in other examples. In Switzerland for fifteen or twenty years a 
succession of these worms were reared in the open air by M. de 
Chavannes, but subsequently the race died out through some 
accident. The moth is banded, and bears four eye-like spots, as 
may be seen in our figure (fig. II) ; the caterpillar has the cha¬ 
racteristic of A. Cynthia, shown in our preceding article, though 
superior in size. 
Mr. Manuel, Manager of the Wild Silk Agency at Rangoon, has 
communicated several facts relating to the history of the Tussur 
silkworm, which is generally fed upon some species of Oak. He 
perceived, having had large numbers under observation, that 
they much preferred light to darkness, for when they were sup¬ 
plied with leaves in jars that were covered by thin white discs, 
the silkworms all endeavoured to reach a spot in or near these 
while they were reposing. Not uncommonly they devoured the 
cast-off skin after each moult, making also their first meal of the 
egg-shell that they had quitted. He suggests that these and other 
caterpillars may occasionally free themselves from the old skin by 
biting off portions. In their attitudes the Tussur worms vary, 
since part of them will moult with their heads stretched upwards, 
and part with it bent down ; the latter, as a rule, were found to 
moult more readily. There has as yet been a difficulty in getting 
specimens of this insect, A. Mylitta, for British experiments, some 
further trials might advantageously be made. The remark applies 
to all the Oak-feeding species of silkworm, that if it is possible to 
Fig. 14.—Moth of Attacus Mylitta. 
place them upon trees or shrubs growing in the usual way, the 
worms do far better than when they are living upon the leaves of 
twigs cut off. 
Attacus Roylei, the silkworm of the Himalayan Oak, has been 
tried both in Europe and America, some districts of Germany 
suiting it very well. In appearance this is more like the celebrated 
silkworm of Japan, called B. Yama Mai (to be hereafter noticed) 
than the others of its genus, and a crossing has been tried between 
this moth and B. Pernyi. The cocoon of the hybrid is excellent, 
superior to the natural cocoon of A. Roylei. The worm is also 
easier to rear ; though M. Wailly of Clapham has fed with 
tolerable success the silkw'orm of the Himalayas in that London 
suburb, and obtained the above hybrid as well. During the 
winter the species is in the pupal state, moths emerge in May or 
June, and the silkworms feed through the summer. Upon the 
ordinary cocoon of A. Roylei there is a tough outer envelope 
which is of no value; the silk below it is therefore less in quantity, 
