CHAP. XXVII.] 



OF TUB MOLUCCAS. 



399 



aad on insects or crtistacea. The female lays from three 

 to five large and beautifully shofjrcened green e<,'g3 upon 

 a bed of leaves, the male and female sitting upon tliem 

 alternately for about a month This bird is the helmeted 

 cassowary (Casuarius galeatus) of natumUsts, and was for 

 a long time the only species known. Others have since 

 been discovered in New Guinea, Kew Britain, and Koith 

 Australia. 



It was in the Moluccas that I first discovered luidoubted 

 cases of "miuiiery" among birds, and these are so curious 

 that I must briefly describe them. It will be as well, 

 however, first to ejcplain what is meant by mimicry in 

 natural Iiititory. At page 131, 1 have described a butterfly 

 which, when at rest, so closely resembles a dead leaf, 

 that it thereby escapes the attacks of its enemies. This 

 is termed a " protective resemblance," If however the 

 butterfly, being itself a savoury morsel to birdsj had 

 closely resembled another butterfly winch was disagreeable 

 to birds, and therefore never eaten by them, it would be 

 as well protected as if it resembled a leaf ; and tliis is what 

 has been happily termed " mimicry " by Mr. Bates, who 

 first discovered the object of these curious external imita- 

 tions of one insect by another belonging to a distinct 

 genus or family, and sometimes even to a distinct 

 order. The clear-ivinged moths which resemble wasps 

 and hornets are the best examples of " mimicry " in our 

 own eountiy. 



For a long time all the known cases of exact resem- 

 blance of one creature to quite a different one were con- 

 fined to insects, and it was therefoi'c with gi-eat pleasure 

 that I discovered in the island of Bourn two birds which I 

 constantly mistook for each other^ and which yet belonged 

 to two distinct and somewhat distant families. One of 

 these is a honeysucker named Tropidorhynchus bouruensis, 

 and the other a kind of oriole, wliich has been called Mimeta 

 bouruensis. The oriole resembles the honeysucker in the 

 following particulai-3 : the upper and under surfaces of the 

 two birds are exactly of the same tints of dark and light 

 brown ; tlie Tropidorhynchus has a large bare black patch 

 round the eyes ; this is copied in tlie Mimeta by a patch of 

 black feathers. The top of the head of the Trapidorbyu- 



