Notes on the interbreeding of different races of silkworm. [Forwarded with explanatory note by Edward Blyth.]
Facts on the interbreeding of different races of Silkworms, by F. Bashford Esq, of Surdah Factory, Lower Bengal. N.B. M
I imported some Silk worms' Eggs from China & France, to cross & improve the Madrassee breed in India. the French Eggs hatched, & the Cocoons I got were as good as the originals in France, & of the same color—yellow—
French & China worms are annuals, our Bengal Madrassee monthly—
The China Eggs hatched, theengal Madrassee monthly—
The China Eggs hatched, the worms were small, & Cocoons small, & of a white color, I have no idea what their originals were. I procured both Male & Female of our Bengal Yellow Madrassee Cocoons, the race is not indigenous, but originally imported, it is supposed & I selected them in consequence, fancying the cross would succeed better than with a pure race. they joined readily with the French & China French Males to Bengal Females, & Bengal (Madrassee) Males to French Females— the Eggs were laid in due course, those of the French Male, & Madrassee Female, (the usual size of Bengal Eggs) remained Yellow in color till two or three days before hatching (about 7 days) when a little black speck was observable, the next & following day, they became all dark, & immediately hatched—
The Eggs from the French Female & Bengal Madrassee Male large in size as in France, were yellow also on first being deposited—but remained so for about 2 days only, when they changed to a dark slate color, similar nearly to the color of the Eggs I imported, & they have remained so ever since, about a month, this leads me to fancy the cross has not altered their nature, & that they will not hatch till the usual period with French Eggs in France, a year after—
The Cocoons I have got from the Cross between the French Male & Bengal female, are in appearance very like the original French exactly so in color, & nearly as good in quality— I have no Eggs from this cross as yet.
The China Female & Madrassee Male gave Eggs about the size of the Madrassee, they turned dark on 2
The China Male & Bengal Female, gave Eggs & produced in the same way as the French Male, but have given Cocoons quite opposite in color, viz. yellow, & about double the size of the originals— they have eaten out, & the Moths are more than double the size of their Parents, & very strong— I have Eggs from this cross, & they have turned dark in the same way, as did the China Female with the Madrassee Male, which makes me fear that the hatching will not take place on 8
- f1 1690.f1Dated by Blyth's reference at the top of the letter to Bashford's arrival in England via the Alfred. The Alfred arrived at Gravesend on 3 July 1855 (The Times, 4 July 1855, p. 12).
- f2 1690.f2Blyth forwarded Bashford's letter to CD adding this explanatory note at the top of the letter.
- f3 1690.f3Bashford's letter had evidently been pinned to other notes and memoranda from Blyth.