RESEMBLANCES AMONG ANIMALS. 75 
semblance that deceives. As this kind of resemblance 
has the same effect as voluntary imitation or mimicry, 
and as we have no word that expresses the required 
meaning, “mimicry”? was adopted by Mr. Bates (who 
was the first to explain the facts), and has led to 
some misunderstanding ; but there need be none, if 
it is remembered that both “mimicry” and “ imita- 
tion” are used in a metaphorical sense, as implying 
that close external likeness which causes things un- 
like in structure to be mistaken for each other. 
Mimiery. 
. It has been long known to entomologists that certain 
insects bear a strange external resemblance to others 
belonging to distinct genera, families, or even orders, 
and with which they have no real affinity whatever. 
The fact, however, appears to have been generally con- 
sidered as dependent upon some unknown law of “ana- 
logy ”—some ‘system of nature,” or ‘ general plan,” 
which had guided the Creator in designing the myriads 
of insect forms, and which we could never hope to 
understand. In only one case does it appear that the 
resemblance was thought to be useful, and to have been 
designed as a means to a definite and intelligible 
purpose. The flies of the genus Volucella enter the 
nests of bees to deposit their eggs, so that their larve 
may feed upon the larvae of the bees, and these flies 
are each wonderfully like the bee on which it is 
parasitic. Kirby and Spence believed that this resem- 
blance or “mimicry”? was for the express purpose of 
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