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The Variation of Animals and Plants

in honey, so that some bee-keepers even distinguish between swarming and honey-
gathering bees, this is a habit which has become second nature, caused by the customary
mode of keeping the bees and the pasturage of the district. For example, what a
difference in this respect one may perceive to exist between the bees of the Luneburg
heath and those of this country!" . . . "Removing an old queen and substituting a young
one of the current year is here an infallible mode of keeping the strongest stock from
swarming and preventing drone-breeding; whilst the same means if adopted in Hanover
would certainly be of no avail." I procured a hive full of dead bees from Jamaica, where
they have long been naturalised, and, on carefully comparing them under the microscope
with my own bees, I could detect not a trace of difference.
This remarkable uniformity in the hive-bee, wherever kept, may probably be accounted
for by the great difficulty, or rather impossibility, of bringing selection into play by
pairing particular queens and drones, for these insects unite only during flight. Nor is
there any record, with a single partial exception, of any person having separated and bred
from a hive in which the workers presented some appreciable difference. In order to form
a new breed, seclusion from other bees would, as we now know, be indispensable; for
since the introduction of the Ligurian bee into Germany and England, it has been found
that the drones wander at least two miles from their own hives, and often cross with the
queens of the common bee. The Ligurian bee, although perfectly fertile when crossed
with the common kind, is ranked by most naturalists as a distinct species, whilst by others
it is ranked as a variety: but this form need not here be noticed, as there is no reason to
believe that it is the product of domestication. The Egyptian and some other bees are
likewise ranked by Dr. Gerstäcker, but not by other highly competent judges, as
geographical races; he grounds his conclusion in chief part on the fact that in certain
districts, as in the Crimea and Rhodes, they vary so much in colour, that the several
geographical races can be closely connected by intermediate forms.
I have alluded to a single instance of the separation and preservation of a particular stock
of bees. Mr. Lowe procured some bees from a cottager a few miles from Edinburgh, and
perceived that they differed from the common bee in the hairs on the head and thorax
being lighter coloured and more profuse in quantity. From the date of the introduction of
the Ligurian bee into Great Britain we may feel sure that these bees had not been crossed
with this form. Mr. Lowe propagated this variety, but unfortunately did not separate the
stock from his other bees, and after three generations the new character was almost
completely lost. Nevertheless, as he adds, "a great number of the bees still retain traces,
though faint, of the original colony." This case shows us what could probably be effected
by careful and long-continued selection applied exclusively to the workers, for, as we
have seen, queens and drones cannot be selected and paired.
SILK-MOTHS.
These insects are in several respects interesting to us, more especially because they have
varied largely at an early period of life, and the variations have been inherited at
corresponding periods. As the value of the silk-moth depends entirely on the cocoon,
every change in its structure and qualities has been carefully attended to, and races
 
 
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