9088 Entomological Society. 
chiefly useful in giving greater power of turning or twisting. As to the enquiry 
whether he had seen the butterflies actually pursued, he admitted that he had not to 
any great extent; he offered his explanation as a theuretical one; but he thought it 
could scarcely be doubted that butterflies were subject to the attacks of numerous 
depredators. 
Paper read. 
The Secretary read a paper, “‘ On the Reversion and Restoration of the Silkworm,” 
by Captain Thomas Hutton, F.G.S., of Mussooree, N.W. India. 
The author attributed the enormous loss of silkworms by “ muscardine” and other 
diseases, and the consequent diminution of the crop of silk, to the combined effects of 
bad and scanty food, want of sufficient light and ventilation, too high a temperature, 
and constant interbreeding for centuries of a debilitated stock. He asserted that there 
was no such thing now in existence as a perfectly healthy domesticated stock of silk- 
worms; and moreover, that it was useless to seek for healthy seed, fur whether in 
Europe, Persia, India or China, the worms were all equally degenerated, or, if there 
were a difference at all, it was in favour of the European race. He had for several 
years been experimenting upon Bombyx Mori, with a view, if possible, to reclaim the 
worms, to restore to them a healthy constitution, and to induce them to revert from 
their present artificial and moribund condition to one of vigour and permanent health. 
The occasional occurrence in a brood of one or more dark gray or blackish-brindled 
worms—the “ vers tigrés” or “ vers zébrés” of the French—contrasting strongly with 
the pale sickly hue of the majority, must have been noticed by all who have had 
experience in rearing silkworms; such occurrences have been always spoken of as 
indicating variety arising from domestication. The author had endeavoured, by a 
series of experiments, to ascertain the cause of this phenomenon, his conviction being, 
either that the species had at some time or other been crossed by another of different 
colours, and that Nature, as sooner or later she always would do, was making an effort 
to separate them, or that the original colour of the worm had been dark, and an effort 
was being made to revert from a sickly condition to the original healthy starting-point. 
He accordingly picked out all the dark-coloured worms and reared them separately, 
allowing the moths to couple only inéer se, and the same with the white worms. In 
the following spring the one batch of eggs produced nearly all dark brindled worms, 
whilst the other batch produced white worms, sparingly interspersed with an occasional 
dark one; these latter were removed into the dark batch, which was also weeded of its 
pale worms. In the third year the worms were still darker than before, and were 
always larger and more vigvrous than the pale ones, giving larger and better-stuffed 
cocoons. Just as the eggs of the third year had been collected, a violent gale of wind 
upset the whole, but in the spring of 1862 the author recommenced de novo, and went 
over the same ground again. The few dark worms picked out escaped disease 
altogether, though reared in the same manner, in the same room, in the same 
temperature, on the same quality of food as, and in close contiguity with the others. 
In due time they spun cvcoons, and produced moths, which, coupling inter se, 
deposited a fair stock of eggs, with which the experiments were continued in 1863. 
The eggs began to hatch on the 16th of March, and no sign of disease was apparent 
until the moths came forth, when many still showed defects in the malformation and 
dark spotting of the wings. As compared, however, with the previous year there was 
decided improvement; still there were too many white worms in the brood, but there 
was no symptoms of disease, the worms attained a larger size by a quarter of an inch 
