156 Captain T. Hutton on the 
domestication had commenced, and that it actually is such is 
proved, not only by the colours remaining permanent in the black 
race, which they do not in the white race, but by the acquisition 
of qualities which originally belonged to the species and which 
the pale-coloured worms do not exhibit. Thus, as the General 
truly observes, ‘‘ the recovery of the colour of their first ancestors 
has caused them to be distinguished by more broadly defined 
natural qualities.” 
Still further, we gather from the observations of M. Boitard, 
that “the black worm, which is so often met with in the north of 
France, is absolutely unknown in Italy; and yet the eggs, which 
in France will produce them, are often purchased in Italy.” 
Here it is plain, if my views are correct, that climate tells upon 
the constitution of the insect even in Europe, and that in Italy, 
where the temperature is bigh, the black worm is unknown, 
simply because the heat of the climate, combined, perhaps, with 
too high a temperature in the houses, enervates the worm and 
causes it to depart further from its original type than it does in 
France, where the climate is colder and more favourable to the 
general health of the insect. 
Again, the same writer informs us, that ‘in Lombardy the 
worm which produces the white silk will constantly furnish nine 
white coccons to one yellow one, although in France, no matter 
how much care may have been bestowed upon the worm, the 
yellow cocoons will always far out-number the white ones.’ 
Now I have long entertained the idea, that the production of 
white cocoons is (except in cases where that colour is permanent 
in all climates) a strong sign of degeneracy, proceeding from 
weakness of constitution, the rather that such white cocoons are 
always more abundant where the temperature is high, than in 
more temperate climates. Hence in Italy the worms, which in 
that high temperature will constantly produce an excess of white, 
will in a more favourable situation and circumstances produce an 
excess of yellow, cocoons.. Thus, the Loro-pooloo of Bengal 
(B. textor, nov.), which there and in China, as a rule, produces 
white cocoons, when reared in the colder climate of Mussooree 
yields almost all yellow cocoons; while to find a white cocoon 
among the worms of Cashmere (B. Mori) is altogether the ex- 
ception. 
Hence I come to the conclusion, that the whiteness of the 
worm and the white cocoons are both indications of failing con- 
stitution, evidencing the existence of a higher temperature and of 
a more thoroughly artificial treatment than are conducive to the 
