THE TECHNOLOGIST. [Nov. 1, 1864. 



176 ON THE REVERSION AND 



my entertaining the most sanguine hopes of ultimate success, provided 

 the same system be carried on for a few years longer, when it will of 

 course depend upon the cultivator to maintain the advantages thus 

 secured. 



Of all the groups comprised within the family of the Bombycidce that 

 in which the genus Bombyx is contained is, perhaps, in a commercial 

 point of view, the most interesting and the most valuable. This genus 

 contains, besides a few wild indigenous species widely scattered over the 

 continent of India, all those long domesticated species popularly known 

 as " silkworms" which were centuries ago imported into Europe from 

 the northern provinces of China, where for many centuries previously 

 they had likewise been kept in a state of domestication. 



Having, however, already, in a paper entitled " Notes on the Silk- 

 worms of India," entered somewhat fully into the history of the Chinese 

 species, I need not here travel over the same ground, but shall call 

 attention to facts not previously noticed, and endeavour, after exposing 

 the folly of insisting, as some still obstinately do, upon the healthy and 

 vigorous constitution of the insects, to show by how very simple a 

 method the worms may be induced to revert from their present artificial 

 and moribund condition to one of vigour and permanent health. 



According to the commonly-received chronology, the discovery of the 

 silkworm in China was made about the year B.C. 2640 ; and the means 

 of reeling off, or unwinding the fibre from the cocoon, being also dis- 

 covered, the regular domestication of the insect at once commenced. 



Whether the species then discovered was in reality that to which 

 naturalists have since assigned the name of Bombyx mori, or whether 

 the discovery of more than one species then occurred, we have now no 

 means of positively ascertaining ; nor, indeed, does it much signify, as, 

 for the present at least, it is with that known and cultivated in Europe 

 as an annual that we have to deal ; but from a paragraph quoted by 

 Mr. F. Moore, from the " Account of the Ceremonies of the China 

 Dynasty," it woidd appear as if more than one species were under culti- 

 vation at the time when the " Account " was written, inasmuch as it con- 

 tains an allusion to a second crop of silk, when it says : " The officer 

 who adjusted the price of horses forbade the people to raise a second breed 

 of silkworms in one season." Now, whatever the Bombyx mori may be 

 when cultivated in Cashmere, Persia, or Europe, it may undoubtedly be 

 made, in a suitable temperature, to produce an autumnal brood; this, 

 however, refers to the worm after having been submitted .to my experi- 

 ments for two or three years, and when, indeed, it is fast travelling 

 back to a state of nature. The same thing occurs likewise with regard 

 to another species, which is also an annual, as far as I can learn, in all 

 countries, except Mussooree in the "Western Himalaya ; this is the Boro 

 Pooloo of Bengal, and Bombyx textor (nobis), which, like the Bombyx 

 mori, yields an autumnal crop when treated in a particular temperature. 

 This fact, indeed, has led some people to declare that the two are but 



