analysis of this effect, and kindred ones, we give also some diagrams — some 

 imitation zebra pictures. Figs. 90, 91, and 92 are photographs of a zebra- 

 shaped model cut out of flat cardboard, and placed amid straws and imita- 

 tion reeds or grasses, artificially arranged. In Fig. 90 the grasses relieve 

 light against a dark background (as in the real zebra photographs by Schill- 

 ings), and the zebra-to-be — now a wild ass (!) — is tinted uniformly with a shade 

 intermediate between background and grasses. Being actually flat, as the 

 real live zebra is made to appear by its full obliterative shading, this mono- 

 chrome model is not revealed by any look of solidity; yet it is visible and rec- 

 ognizable, because its stripeless surface, with its organic and peculiar outline, 

 interrupts and relieves against the striped pattern behind it. In Fig. 91, the 

 same model, against the same background, has been converted into a zebra, 

 by the application of the proper bands or stripes, — and notice the result ! The 

 cardboard figure, standing almost where it stood before, and in exactly the 

 same lighting, has practically disappeared from view. Its sharp bands carry 

 the striate pattern of straws and dusky background across its every part, 

 thereby obliterating it almost completely. (Schillings's zebras didn't hap- 

 pen to have a fully and evenly striped background at the moment when he 

 photographed them,* and therefore the effect of actual background-ma/c/wwg 

 is only f ragmen tarily shown by his pictures.) Fig. 92 shows the same thing 

 over again, with the difference that the striped background is made by imi- 

 tation reeds relieving dark against white paper; the reverse of the former case. 

 These two sorts of background are almost equally well suited to the zebra- 

 pattern, as our pictures show. Both are imitated from nature, the one cor- 

 responding to a landscape with brightly lighted grasses, reeds, or other tall 

 and slender plants, relieving against dark ground or water, or against the 

 shadowed interior mass of their own kind (see Schillings's pictures, Figs. 88 

 and 89), and the other to a landscape in which such plants in somewhat open 

 array relieve darkly against bright sky or water. Again, the shadows of these 

 tall and linear plants — or even of plants more treelike and branching — cast 

 * (not to speak of the extreme abnormality of the lighting). — A. H. T. 



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