480 FIELD STUDY IN ORNITHOLOGY. 



from Gilolo. Yet the oriole lias adopted the same livery whicli else- 

 where is a perfect mimicry. INIay it not therefore be that we have, in 

 this group of bi'owii orioles, the original type of the family undifter- 

 eiitiated? As they spread east and south we may trace the gradation, 

 through the brown striaticm of the New (Juinea- bird to the brighter, 

 green-tinged form of the West Australian and the green plumage of 

 the Southern Aus^tralian, while westward the brilliant yellows of the 

 numerous Indian and African species were developed, and another 

 group, preferring high elevations, passing through the mountain ranges 

 of Gava, Sumatra, and Borneo, intensified the aboriginal brown into 

 black, and hence were evolved the deep reds of the various species 

 which culminate in the crimson of Formosa, Oriolus <(rdcns, and the 

 still deeper crimsons of 0. trailli of the Himalayas. 



It is possible that there may be similarity without mimicry, and, by 

 the five laws of mimicry as laid down by Wallace, very many suggested 

 cases must be eliminated. We all know that it is quite i^ossible to find 

 between species of very different genera extraordinary similarity which 

 is not mimetic. Take, for instance, the remarkable identity of colora- 

 tion in the case of some of the African species Muvronijx and the 

 American t>^tarneUa, or, again, of some of the African Campophafja' and 

 the American Af/ehens. The outward resemblance occurs in both cases 

 in the red as well as in the yellow-colored species of all four groups. 

 But we find that the Macronyx of America and the Canipophaga' of 

 Africa, in acquiiing this coloration, ha\ie departed widely fmmthe plain 

 color found in their immediate relatives. If we applied Mr. Scudder's 

 theory on insects, we must imagine that the prototype form has become 

 extinct, while the juimicker has established its position. This is an 

 hypothesis which is easier to suggest than either to prove or to disprove. 

 Similar cases may frequently be found in botany. The strawberry is not 

 indigenous in Japan, but in the mountains there I found a potentillain 

 fruit which absolutely mimicked the Alpine strawberry in the minutest 

 particulars, in its runners, its blossoms, and fruit ; but the fruit was simply 

 dry pith, supporting the seeds and retaining its color without shrinking 

 or falling from the stalks for weeks — a remarkable case, we can not say 

 of unconscious mimicry, but of unconscious resemblance. jNIimicry in 

 birds is comparatively rare, and still rarer in mammals, which is not 

 suri^rising when we consider how small is the total number of the mam- 

 malia, and even of birds, compared with the countless species of inver- 

 tebrates. Out of the vast assemblage of insects, with their varied 

 colors and patterns, it would be strange if there were not many cases 

 of accidental resemblance. A strict application of Wallace's five laws 

 would perhaps, if all the circumstances were known, eliminate many 

 accepted instances. 



As to cases of edible insects mimicking inedible-, Mr. Poulton admits 

 that even unpalatable animals have tiieir special enemies, and that the 

 enemies of palatable animals are not indefinitely numerous. 



