72 Introduction: Variation. 



The Kingfisher Melidora of New Guinea, a curious form with a hooked bill, 

 is held by Sharpe to be the lowest type of the family, and Cittura of Celebes 

 and Sangi has the nearest affinities with it, but wants the maxillary hook. 

 When quite young Cittura has this hook (p. 307). Though not a feather- 

 character, this point is of equal significance. 



It has been already remarked that, when the two sexes are not alike, one 

 (usually the female) seems to show a lower development than the other. It is 

 probable that such females preserve more ancestral features than the males, 

 which have acquired more new features than have the females; yet direct proof 

 of this is hard to find. Among Celebesian birds, a female of Psitteuteles meyeri 

 displays, as mentioned above, a trace of the yellow ancestral wing-band; and 

 the rackets of the females of Prioniturus are seldom so long as in the males. 

 Indii-ect proof of the phylogenetic value of the female plumage is furnished 

 when the young of both sexes are like the mother, for such facts as those given 

 above render it pretty certain that the young tend to display ancestral characters. 

 It sometimes hap])ens that the mother and young of one species resemble the 

 adults of both sexes of another species less highly developed than the male of 

 the first. 



These considerations place in the hands of the student of geographical 

 distribution an im])()rtant and (to ourselves) new means of proof in tracing the 

 land of origin of particular species or genera — provided that our sup])osition be 

 admitted that emigrants, cut off" from their native country, are more likely to 

 get altered than the stayers-at-home.') In this manner it has proved possible to 

 trace the genus Loriculus (of which over 20 geograi)hical species are known 

 between India and New Guinea) as having originated in Asia, and to construct 

 a genealogical tree of two main branches showing the descent of the species 

 from the Asiatic L. vemalis or its ancestor, this s]iecies being supposed to have 

 extended its range in process of time across the Archipelago, undergoing some 

 new modification with each change of habitat, viz. with each new isolation. The 

 more eastern forms now throw back by their females and young to more western 

 forms, and in this manner the two branches of the genus finally converge upon 

 a form like L. vernalis. The case is fully discussed, pp. 160 — 169 of text, 

 Map VI. 



On similar grounds it is possible to trace the origin of the Blue-and-rufous 

 Flycatcher of Kalao Island to Celebes. The sexes are slightly different, and 

 the male of Siphia kalaoensis is the most specialized member of its group; its 

 female is like the male from Djampea Island, <S. djampeana; the female from 

 Djampea is like the male from Saleyer Island and Celebes, <S. hanyumas, which is 

 thus indicated as having emigrated first to Djampea and later from there to 

 Kalao. 



In the same manner the blue back of the young of Pelargopsis melanurhyncha 



'; For proof see variation in Sangi and Talaut, anica, p. ,0A\ 



