274 Colour and the Struggle for Life 
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 colouring. Quiescence is an essential element in the 
protective resemblance to a stone—probably even more indispensable 
than the details of the form and colouring. Although Burchell 
appears to overlook this point he fully recognised the community 
between protection by concealment and more aggressive modes of 
defence ; for, in the passage of which a part is quoted above, he 
specially refers to some earlier remarks on p. 226 of his Vol. We 
here find that when the oxen were resting by the Juk rivier (Yoke 
river), on July 19, 1811, Burchell observed “Geranium spinosum, with 
a fleshy stem and large white flowers... ; and a succulent species of 
Pelargonium. ..so defended by the old panicles, grown to hard woody 
thorns, that no cattle could browze upon it.” He goes on to say, “In 
this arid country, where every juicy vegetable would soon be eaten 
up by the wild animals, the Great Creating Power, with all-provident 
wisdom, has given to such plants either an acrid or poisonous juice, 
or sharp thorns, to preserve the species from annihilation...” All 
these modes of defence, especially adapted to a desert environment, 
have since been generally recognised, and it is very interesting to 
place beside Burchell’s statement the following passage from a letter 
written by Darwin, Aug. 7, 1868, to G. H. Lewes: “That Natural 
Selection would tend to produce the most formidable thorns will be 
admitted by every one who has observed the distribution in South 
America and Africa (vide Livingstone) of thorn-bearing plants, for 
they always appear where the bushes grow isolated and are exposed 
to the attacks of mammals. Even in England it has been noticed 
that all spine-bearing and sting-bearing plants are palatable to 
quadrupeds, when the thorns are crushed®.” 
Adaptation and Natural Selection. 
I have preferred to show the influence of the older teleology upon 
Natural History by quotations from a single great and insufficiently 
appreciated naturalist. It might have been seen equally well in the 
pages of Kirby and Spence and those of many other writers. If the 
1 Loc. cit. pp. 310, 311. See Sir William Thiselton-Dyer ‘‘Morphological Notes,” x1.; 
“Protective Adaptations,” 1.; Annals of Botany, Vol. xx. p. 124. In plates vu. va. and 
1x. accompanying this article the author represents the species observed by Burchell, 
together with others in which analogous adaptations exist. He writes: “ Burchell was 
Glearly 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 (Life and Letters of Thomas Henry 
Huzley, London, 1900, 1. p. 457), the facts of the old teleology are immediately transferable 
to Darwinism, which simply supplies them with a natural in place of a supernatural 
explanation.” 
2 More Letters, 1. p. 308. 
