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Apart from the excellent work wliicli Dr. Hans Gadow has been 

 producing in his edition of Bronn's ' Thierreich/ he has written a very 

 important paper on the intestines of birds, entitled '^On the Taxonomic 

 Value of the Intestinal Convolutions in Birds/^ and published in the 

 'Proceedings' of the Zoological Society for 1889. Mr. A. H. Evans 

 has given a very concise summary of the results obtained by Dr. 

 Gadow, in the ' Zoological Kecord ' for 1889, which seems to express all 

 that is necessary : — 



"■ Tlie writer beo^ius this exceptionally lucid and valuable paper with an account of 

 the different varieties of intestinal convolutions in Birds and of their nomenclature. 

 He next discusses, and represents in the plates, the ' taxonomic value of those 

 characters which are exhibited by the modes in which the mid-gut is stowed away in 

 the abdominal cavity ' ; and finds that the arrangements, of which he gives a table, 

 are much more constant than was formerly supposed, both in species and in whole 

 families. He agrees with Fiirbringer in recognizing a combination Coracoruithes. 

 Among the conclusions, apart from this group, we may notice especially the deduction 

 of an affinity between the Columbce, Limicol(s, and Laridce^ the Steganopodes, Herodii, 

 Tubinares, and Spheniscidee, with the intermediate position of the Tubinares between 

 the Laro-Limicol<2 and Steganopodes, and, above all, some unexpected resemblances 

 between the Pelargi and the Raptores diurni. Within the Coracornithes the Coccyges 

 are lowest (somewhat resembling the Gallincs and Ojn'sthocomus) ; the Picidce, 

 Capitonidce, and WiampliastidcB may be collectively termed Pici, and the Coraciidce 

 and Alcedinidce Halcyones, leaving the other Piearian families in close connectiou, 

 with the Striges further off. The Passeres are quite uniform in character." 



A work which also bears upon the classification of the Passeres 

 in particular is Mr. Oates's exposition of the order in the 'Fauna 

 of British India.'' I have already published a long review of this 

 standard work in 'The Field' for 1890^ and have expressed my views 

 on the arrangement of Mr. Oates's work. The fundamental character 

 on which he arranges his Passeres is the style of plumage of the young. 

 The first naturalist to recognize the value of this peculiarity was appa- 

 rently Mr. Seebohm, who, by the character of the nestling plumage^ 

 separated the Thrushes from the Warblers {cf. Cat. B. Brit. Mus. v. 

 pp. 1, 2) . That the coloration of the young plumage is of great value in 

 arranging the Passeres will doubtless be admitted sooner or later ; for 

 there is no character which gives us so good a clue to the ancient 

 plumage of a group of birds as the style of the immature individuals 

 at the present day. Thus we can easily imagine that the progenitors of 

 the Thrushes, Chats, Eedstarts, Nightingales, &c. were all profusely 

 spotted, and that the more uniform plumage has been a matter of 

 after-acquirement. In 1871 I pointed out in the ' Birds of Europe ' 

 the method by which Kestrels {Cerchneis tinnuncuhis) gain the adult 

 plumage, shadowing forth by their change of garb in the present day 

 the probable methods by which the first blue-headed and blue-tailed 

 males were evolved from a stock wherein both sexes were alike rufous, 

 such as is still seen in Cerchneis rupicoloides of South Africa. 



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