1899] ON MIMETIC RESEMBLANCES 123 



with the yellow colour of the animal's belly, where it lodged ; the 

 second brown, from the lizard's head ; but the third, which was 

 clinging to the parti-coloured scales of the neck, had its body parti- 

 coloured, the hues corresponding with the individual scales which they 

 covered. The adaptation of the two first specimens in colour to the 

 parts to which they adhered is sufficiently remarkable, but the third 

 case was most extraordinary." 1 



Without explaining how " the trick is done," the word " adaptation " 

 seems best serviceable, both for mimetic coloration and mimetic forms. 

 Thus, taking the Australian marsupials as examples, we have the 

 well-known imitations of placental Mammals occurring among them 

 as a result of similar habits, but certainly not of protection arising 

 from similarity. Thus, Andrew Murray observes how " Antechinus 

 minutissimus, the kangaroo mouse, closely mimics Mus clelicatulus ; 

 the flying Marsupial Petaurus is a close counterpart in outward appear- 

 ance of some of the flying squirrels. One or two of the Phascogales or 

 Antechini resemble the jerboa ; Peragalea lagotis has considerable 

 resemblance to a hare, and carries its habits as well as its ears, 

 making a form in the grass like it." 2 



That similar usages have educed similar structures, without affinity, 

 is seen in cases where only certain parts of animals are mimetic. Thus 

 the paddle of a whale resembles that of the Ichthyosaurus, and its tail 

 that of a homocercal fish-tail, though it lies in a horizontal plane 

 instead of a vertical one. Such resemblances are too numerous to 

 mention ; but there is no question of protective resemblances or of 

 natural selection in the matter. 



Inductive evidence of this kind brings us to the inevitable con- 

 clusion, not only that like causes have produced similar results, but 

 that they are the direct outcome of the joint action of the outward 

 physical conditions of life and the inward adaptive powers of proto- 

 plasm, coupled with the habits of life. Beyond that we do not seem 

 capable of going. 



Mimicry in Plants. 



Objections have been raised as to the applicability of the term 

 " mimicry " to animals, and so a fortiori in regard to plants ; for the 

 word originally meant an actual imitation by a human being in gesture 

 and manner. It might be conscious as in dumb-show, or unconscious 

 as under delirium. 



Now in mimetic insects the mimicry consists in the form and 

 colour resembling others of no affinity, or in being like external objects, 

 as well as in the adoption of similar habits. Thus, in the case of the 

 " stick " insects, it is said that they allow their legs to assume un- 

 sym metrical positions when at rest, so as to resemble a branch with 



1 "Himalayan Journals" (Minerva ed. p. 26). 

 2 "The Geographical Distribution of Mammals," p. 53. 



