246 Correspondence. [ 2n d April 



differences are they to be created ? Nay, I will go further and 

 say that if trivial differences are to be suppressed in the considera- 

 tion and determination of species, one-third, at least, of Australian 

 species will " go down before the scythe of exhaustive comparison." 

 faking Australian Passerines, I ask what else but trivial differ- 

 ences separate such species as Gould's Micrceca assimilis from 

 Latham's M. fascinans, his Malurus elegans from M. amabilis, 

 M . pulckerrimus , and M. lamberti, and any one of them from the 

 other, and his Artamus melanops from A. venustus ; Dr. Sharpe's 

 Petrceca campbclli from P. leggii ', his Cinclosoma castancothorax 

 from C. marginatum, his Gerygone cinarescens from G. albigularis ; 

 Count Salvadori's Platycercus xanthogcnys from P. icterptis ; De 

 Vis' Acanthiza squamata from A. reguloides ; Zietz's Acanthiza 

 tcnuirostris from the same species ; North's Climactcris super- 

 ciliosa from C. erythrops, and his Malurus assimilis from M. 

 lamberti, and so on. If the President's view of the subject is 

 right, then all these ornithologists are wrong. 



The President's remarks imply that differences in structure 

 of bills and legs are of slight importance. It is difficult to admit 

 this, having regard to the fact that the chief characters which 

 distinguish Passerines from the rest of the class " Aves " are the 

 palate and the " arrangement " of the deep plantar tendons of 

 the foot. The powerful bill and claws {inter alia) of the 

 Crow help to place him at the head of the Oscines. I 

 appreciate, of course, that there are degrees of difference. Let 

 me present the case of Melithreptus brevirostris and the Western 

 modified form of M. Icucogcnys, in which latter (excluding other 

 minor differences) the bill is much shorter and finer. With 

 such a modification, is it not probable that if the two species 

 exchanged habitats, the Western form would eventually perish 

 or become diminished in number by reason that his shorter bill 

 would not enable him to extract nourishment from food stores 

 which the bird with the longer bill could ? Where a modification 

 an important organ such as the bill (and which is to a bird what 

 hands and mouth are to a man) is permanent and not variable, 

 and without intergrades, then such a fact is to my mind of much 

 greater importance in the consideration and determination of 

 species than the presence or absence of an eyebrow, or difference 

 in a shade of blue of the plumage, or the colour of a forehead 

 patch. I am aware that I am trenching on debatable ground, 

 but as the Check-List Committee will begin their labours 

 this year, the discussion of the subject, with the addition 

 of the President's recorded impressions, should prove most helpful 

 in their deliberations. — Yours, &c, 



ALEX. WM. MILLIGAN. 



[Whether our ex-President was justified in saying that Cala- 

 manthus montancllus appeared to be a sub-species of C. fuligin- 

 nosus, " altered by climatic and topographical conditions," must 

 remain an open question until further evidence be forthcoming. 



