APPENDIUES. 358 
entirely futile to attempt to explain the nature of providential 
arrangements, and point out the secret purposes for which 
vither apparent analogies or discrepancies were devised. The 
best explanations offered, indeed, are too full of contradictions 
to be for a moment seriously accepted as revelations of in- 
tended purpose. As aready example of the contradictions to 
which such speculations must be liable, I may mention here, 
that although the parasitic bee, which infests the nests of 
Euglossa dimidiata, is entirely unlike the harvesting-bee whose 
home he invades, yet the doubly-unfortunate Huglossa has a 
second enemy, in the form of a gigantic Diptera, whose simi- 
larity to the bee is most curious. This enormous fly-bee, 
Astlus fasciatus, has, it is true, only two wings, but these being 
of deep brown to half their length, and transparent for the 
remainder, bear an extraordinary general resemblance to those 
of the bee; while the colouring of this handsome insect being 
nea~ly identical with that of the bee, and the size and shape 
of the markings being almost identical, the general resemblance 
becomes very remarkable; hence the conspicuous appearance 
of one enemy is rendered utterly useless as a defence, while 
the seemingly perfect disguise of another apparently favours 
his fatal entrance to the nest. 
There is a handsome bee, Yylocopa nigrita (the female); it is 
a native of Sierra Leone, and is remarkable for the fuil deep 
velvety black of the greater part of the body, while the sides of 
the abdomen are conspicuously fringed, and partly covered, 
with milk-white furry hairs; the effect of which calls to mind 
the appearance of an aged negro of the same part of the 
African coast, whose woolly hair has become white with age. 
The legs, also, are thickly fringed on one side with a similar 
white fur, and the “iace” is white, with large brown eyes. 
The wings are nearly opaque, and of deep, dull purple, with a 
metallic gloss, bronzy-red towards the extremities. The Dip- 
tera, or two-winged counterpart of this insect, has all the 
characteristic contrasts of black and white, similarly disposed, 
even to the white face and brown eyes; while the opaque, 
iridescent wings are precisely similar in tone and colour. The 
somewhat longer legs, the single pair of wings, and the dif- 
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