BURCHELL AND ADAPTATION 97 



'The intention of Nature, in these instances, seems to 

 have been the same as when she gave to the Chameleon the 

 power of accommodating its color, in a certain degree, to 

 that of the object nearest to it, in order to compensate for 

 the deficiency of its locomotive powers. By their form and 

 color, this insect may pass unobserved by those birds, which 

 otherwise would soon extirpate a species so little able to 

 elude its pursuers, and this juicy little Mesembryanthemum 

 may generally escape the notice of cattle and wild animals.' ' 



Burchell here seems to miss, at least in part, 

 the meaning of the relationship between the 

 quiescence of the Acridian and its cryptic colour- 

 ing. It is a relationship of co-operation rather 

 than compensation ; for quiescence is an essential 

 element in the protective resemblance to a stone 

 probably even more indispensable than the details 

 of the form and colouring. Furthermore, the 

 chameleon can make certain movements quickly 

 enough when occasion requires. My friend Pro- 

 fessor Lloyd Morgan has seen an African cha- 

 meleon, when a snake was brought near it, 

 instantaneously quit its hold of the branch, draw 

 in its legs, and fall like a stone to the ground. 

 Although Burchell appears to overlook this point 



1 Ibid., 310, 311. See Sir William Thiselton-Dyer, ' Morpho- 

 logical Notes,' xi. ; ' Protective Adaptations,' i. ; Annals of Botany, 

 xx. 124. In plates vii. viii. and ix. accompanying this article, the 

 author represents the species observed by Burchell, together with 

 others in which analogous adaptations exist. He writes : ' Burchell 

 was clearly on the track on which Darwin reached the goal. But 

 the time had not come for emancipation from the old teleology. 

 This, however, in no respect detracts from the merit or value of his 

 work. For, as Huxley has pointed out (Huxley's Life and Letters, 

 1900, i. 457), the facts of the old teleology are immediately transfer- 

 able to Darwinism, which simply supplies them with a natural in 

 place of a supernatural explanation. 



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