76 The Ottawa Naturalist. [Oct. 



enemy. The honey bee has, of course, many mimics, of which 

 the common drone fly is a familiar instance. 



Nor is protective resemblance confined to invertebrates. We 

 find it in animals, birds, fish and various reptiles. The wild 

 rabbit is a common example of it. Not so common, but a more 

 striking instance of it, may be found in the zebra. Travellers in 

 Africa have found themselves at night in the presence of zebras, 

 and only been aware of the fact by their breathing. Had the 

 zebras been black, or had they been white, they would have been 

 easily visible, but in the starlight night, the combination of black 

 and white stripes blend exactly with the twilight, and so render 

 them invisible. 



Some animals, moreover, possess a variable protective resem- 

 blance. We have an example of this in the chameleon, which 

 adapts its colours according to its surroundings, an adaptation 

 which is brought about by the expansion and contraction of cer- 

 tain pigment cells. The same phenomena may be observed in 

 the Arctic hare, and the Arctic fox, animals which change their 

 colour according to the season, brown in summer, and snowy 

 white in winter. Among birds numerous instances of protective 

 resemblance may be noticed; and so too with the eggs of many 

 of our wild birds, which so closely resemble the shingle in which 

 they are laid as to be unnoticeable. 



Thus we find that there are two kinds of mimicry. In the 

 one the mimic is really weak and defenceless, but by assuming 

 the appearance of some better armed and perhaps savage species, 

 acquires also the latter's evil reputation. This is called Batesian 

 mimicry. In the other we have the real hard cases, creatures 

 which are as well protected by unamiable qualities as they well 

 can be; and which imitate equally disagreeable beings merely 

 for the sake of the additional free advertisement of their ill quali- 

 ties which the latter afford. This is called Mullerian mimicry. 



Mimicry depends for its effective expression upon the power 

 that all the higher animals have of memorizing their experiences. 

 The puppy which captures the bee and is stung learns to avoid 

 such dangerous playthings. In this way the death of one or two 

 individuals frees the whole species from danger of attack by that 

 particular puppy. Moreover, any other kinds of bees, or of other 

 insects resembling in appearance the first one, would also be looked 

 upon with suspicion and avoided. So that the deaths of 

 these one or two individuals would have the effect of protecting 

 every kind of insect that resembled them in appearance. 



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