84 Silks and Silkworms. [February, 
soon damaged by wearing. That the lustre and the beauty 
of the fibre are sacrificed needs no demonstration. 
The plea of cheapness is of the less value because the 
reduction of price to the consumer is never in proportion to 
the additional profit of the manufacturer, and still less to 
the deterioration of the goods themselves. We are some- 
times told that the public “ will have ” weighted silks : this 
is the usual plea of sophisticators. But as public taste has 
been artfully corrupted, it would resume a more healthy tone 
if the fraud were at once sternly suppressed. Meantime the 
best reply to the weighters and loaders is to produce genuine 
silk in such quantity as to lessen the temptation to fraud. 
If this desirable end is gained great credit must accrue to 
the government of India, and, more than to any other man, 
to Mr. Wardle. 
I will now take leave to make a few remarks on the ento- 
mological side of the subject. We cannot fail to notice the 
existence of two hybrid silkworms which are produced not 
as physiological rarities, but in quantity, so as to be com- 
mercially available. The so-called “ Ailanthus silkworm ” 
of Europe is a cross between two species of Attacus, the A. 
cynthia of China and the A. ricini of Bengal. This hybrid 
was first experimentally produced in France under the care 
of M. Guerin-Meneville, and has been successfully intro- 
duced into various countries. Again, Anthercza Yama-mai, 
of Japan, has been crossed in France with Attacus Pernyi of 
North China, the hybrid inseCt being exceedingly hardy. 
These fadts are commended to the notice of such writers as 
still think it necessary to deny the permanent fecundity of 
hybrids. 
Mr. Wardle, in his work, not merely figures several of the 
most important species in their successive states as larva, as 
pupa in the cocoon, and as the mature moth, but he has 
described and figured the scales from the wings of several 
species. The value of characters drawn from these scales 
for the distinction of species, or even genera, is very doubt- 
ful. Mr. Wardle’s figures all show corredtly the insertion of 
the stem or shaft to the body of the scale as it occurs in all 
the main groups of the Heterocera ; that is, the stem is 
attached, as is the stalk to (e.g.) a laurel-leaf, whilst in the 
Rhopalocera it is inserted in a kind of notch between two 
projections. But in other respedts the scales are of the less 
diagnostic value, because in different parts of the wing of 
one and the same species they vary as much as they do in 
different species : there is moreover, I believe, in every case 
a double layer of scales, the upper and the under stratum 
