( 295 ) XIV. On the Reversion and Restoration of the Silkicorm (Part II.); with Distinctive Characters of Eighteen Species of Silk-producing Bombycidae. By Captain Thomas Hutton, F.G.S., of Mussooree. (Com-municated by Mr. F. Moore.) [Read December 5th, 1864.] According to hitherto received notions all the silkworms now under domestication are mere varieties of one species, and are all placed together under the name of Bombyx Mori ; and yet the difference in habits is alone sufficient to point out the existence of several totally distinct species. This circumstance, when some time since noticed by myself in a letter to Mr. F. Moore of the India Museum, elicited the acknowledgment that Entomologists in Europe had long suspected the fact, but that they were without the means of working out all the necessary details, many of the supposed species not being under cultivation in Europe, while no one in India had deemed it worth while to enter into an investigation of the subject. From the moment, however, in which I first recognized the absolute necessity of endeavouring to arrest the rapid strides which disease was making towards the extinction of the silkworm, I became aware, from actual inspection of the worms through all their changes, of the existence of several species, and I at once determined systematically to set to work for the purpose of ex-tricating each from the dark labyrinth of error and confusion in which it had become involved. Any one at all conversant with the Bombycidce must be aware of the fact that, for the most part, the species will, in the northern and colder districts of their respective countries, be either strictly annuals, or at the most double-brooded, while those species which yield several crops of silk during the year, indicate thereby that they were originally imported into the localities where they are now domesticated, from the warm and more prolific lowland regions of the South. A rapid succession of crops, whether of vegetables or of silk, such as we witness among what are in Bengal termed " monthly worms," is obtainable only, whether naturally or artificially, in a mild climate favourable to the rapid growth of vegetation. To the preservation of such species, when in a state
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