Restoration of the Silkworm. 297 
tible in the size, colour, markings and habits of the worms, and the 
form and texture of the cocoons, have been attributed to the effects 
of climate only. Climate, however, has no such influence, since we 
find each species, in whatever climate cultivated, preserving the 
very same characteristics. If the differences at present perceptible 
were in reality merely the effects of climate and of peculiar treat- 
ment, we might surely expect that when a change of climate and 
treatment was experienced some marked and decided change 
would soon be perceptible in the insects likewise; but this is not 
the case, each retaining at Mussooree, in Oudh, and elsewhere in 
the Northern Provinces, the very same characteristics as when in 
the damp warm plains of Bengal. The characters, in fact, are 
constant, no matter where the insects may be. 
Characters, whether of form, colour or habits, if permanent and 
unchangeable, are to all intents and purposes specific characters, 
and even Mr. Darwin admits that when one of his supposed 
varieties attains to a certain degree of stability, it assumes, pro 
tem., the value and importance of a species until variation again 
commences at some after period among the offspring. 
Under any circumstances, therefore, these insects, whatever 
they may originally have been, having now severally attained to 
permanency of characters, have become true species, and as such 
must be accepted and described. 
Genus Bompyx, Schranck. 
The genus Bombyx appears naturally to divide itself into two 
well-defined sections or sub-divisions, the first comprising all the 
domesticated Chinese species of which the larve have hitherto 
been known to cultivators and men of science as being of a pale 
creamy-white colour, and furnished only with one fleshy or semi- 
horny sharp-pointed spine, springing from the dorsal centre of 
the penultimate segment; the other containing the wild and un- 
cultivated species, whose larve are not only richly variegated 
with a number of bright colours intimately mixed together, such 
as ashy-grey, livid-green, yellow, rufous, ferruginous and black, 
but are likewise furnished with from four to six longitudinally- 
disposed rows of fleshy-or semi-horny spines, all curving back- 
wards, besides one long one on the penultimate segment, placed 
between the two dorsal rows and pointing in the opposite direction. 
Of the insects contained in this last section, one feeds on the 
wild indigenous mulberry tree of the North-Western Himalaya, 
and yields a first-rate silk, which, however, cannot be turned to 
VOL. Il, THIRD SERIES, PART IV.—MARCH, 1865, Z 
