Recently published Ornithological Works. 323 



was ever so little further off in yards, though the return 

 from it cost four hours of the hardest climbing, with heavy 

 odds against return at all ! 



48. Meerwarth on the Moulting of Birds of Prey. 



[Beobaclitiuigeu iiber Vertarbung (oline Mauser) der Schwanzfedeni 

 brasilianisc-her Eaubvcigel, nebst einem Beitrag zur Phylogenese der 

 Raubvogelzeiclmuug. Vou Hermann Meerwarth. Zool. Jabrb. xi.p. Go.] 



This essay is based on a careful study of individuals of 

 four species of Brazilian Raptores {Urubitinga zonura, 

 U. schistacea, Heterospisias meridionalis , and Rostrhamns 

 sociabilis) kept alive at Para, and seems to show most clearly 

 that the tail-feathers of these birds change their colours 

 without moult. Some excellent coloured plates illustrate 

 the observations. No one interested in this much-vexed 

 subject should fail to consult Herr Meerwarth's important 

 memoir. 



49. Mercier on the Ostrich-farm at Maturieh. 



[Une Visite a la Ferme d'Autriicbes a Matarieli, jires de Caire. Bull. 

 Soc. d'Accl. 1898, p. 250.] 



This is an account of a visit paid to the well-known 

 Ostrich-farm at Matarieh, near Cairo [cf. P. Z. S. 1895, 

 p. 400), and contains many particulars of interest. Although 

 the extent of the farm is small (6"25 hectares), it contains 

 about 1500 Ostriches. Contrary to usual belief, Ostriches, it 

 would appear, are strict monogamists, and, as we are informed 

 upon good authority, the pair take turns in incubation. 



50. Mott on the Origin of Organic Colour. 



[Two Papers on the Origin of Organic Colour. By T. F. Mott. 

 8vo. Leicester, 1898.] 



In two essays under one cover Mr. JVIott propounds 

 certain new views concerning the colours of animals. The 

 author has some physical notions which are not altogether 

 easy of comprehension, but which he expounds as the pi-ime 

 causes of colour-phenomena in both animals and plants. 

 He arrives at one result which appears to be in accord with 



