XXV 
method pursued in China in rearing the silk-producing Bombyx Pernyi, 
extracted from a Shanghai newspaper :— 
“Bombyx Pernyi feeds exclusively on oak leaves, producing a reddish 
gray cocoon, from which is spun a fine glossy thread; breeds and forms 
cocoons twice a year, and, unlike Bombyx mori, its chrysalis, after the 
second production, remains in the cocoon till the following spring. Two 
kinds of oaks are used for its food: one with narrow serrated leaves and 
conical acorns, the other with broad and long leaves with short round acorns. 
The latter kind is preferred on account of supplying a larger amount of 
food. The trunks of the oak trees are cut, as will be explained in the 
notes, for two reasons: first, to keep the branches within easy reach; 
secondly, to obtain a better adapted quality of leaves at the requisite time 
of the season. The alternate use of the bushes is necessary to keep up the 
successive production of cocoons without damaging the bushes, which would 
suffer if deprived of leaves twice in the same season, and also to allow 
sufficient time for them to grow. The dissimilarity of treatment between 
the first and second production is simply caused by the difference of time of 
the season in which they take place. At the first production the newly 
hatched worms, if transferred at once on the bushes in the open air, would 
be liable to total destruction by a too great fall of temperature; while no 
such danger is incurred late in summer, when the second production is pro- 
eressing. It can easily be seen that Bombyx Pernyi could be raised 
altogether within doors; but by so doing it would entail more labour in 
keeping it supplied with food, besides requiring the continual cutting of 
fresh branches. This would not only cause a great waste of leaves, but 
limit the supply. 
“ Notes on the Practical System followed in the Province of Shang-tung 
for the cultivation of Bombyx Pernyt. 
“ Five or six years (according to their growth) after the oaks have been 
planted, each trunk is cut off close to the roots about November, and in the 
following year, the new branches springing out round the foot, the truncated 
trees will form into low bushes. The first year after the oaks have been 
cut, the second yearly production of cocoons can only be raised on them, and 
they are afterwards used alternately with others for the consecutive 
cultivation of the first and second yearly productions. In explanation of 
the above, let us suppose we have one hundred oak trees. ‘These must be 
divided into two sections; each section to be cut separately at the interval 
of one year. Thus, out of one hundred trees, fifty, cut in November 1870, 
will serve for raising the second yearly production of cocoons in August, 
1871, and the first yearly production in May, 1872; while the other fifty 
trees, cut in November, 1871, will serve for the second yearly production 
in August, 1872, and the first yearly production in May, 18783. Once this’ 
EB 
