208 REPORT — 1844. 



called by Nitzsch in his ' Pterylologiej' is briefly treated of in a memoir read 

 to the Academie des Sciences by M. Jacquemin (Ann. Sc. Nat., 1836, p. 227), 

 who points out several facts which have not been sufficiently attended to by 

 previous ornithologists. 



The various modes by which the changes of plumage in birds at different 

 seasons are effected, whether by actual moulting, by the shedding of a de- 

 ciduous margin to the feather, or by a change of colour in the feather itself, 

 have been investigated by Cuvier, Temminck, Yarrell (Trans. Zool. Soc, 

 vol. i.), and others. Dr. Bachman of Charleston has made some very in- 

 teresting observations on this subject in the case of many of the North Ame- 

 rican birds, which will be found in the ' Transactions of the American Philo- 

 sophical Society,' 1839. 



The subject of moulting, and especially of that remarkable tendency in old 

 female birds to assume the male plumage, is treated of by M. I. Geotfroy St. 

 Hilaire (Ann. Sc. Nat., and Essais de Zoologie Generale, IS^l). See also 

 papers by Dr. Butler in the ' Memoirs of the Wernerian Society,' and by Mr. 

 Yarrell in the ' Philosophical Transactions.' 



M. de la Fresnaye published in the 'Memoires de la Soc. Acad, de Falaise,' 

 1835 (L'Institut, 1 837), a paper on melanism, or a supposed abnormal tendency 

 in the Raptores to acquire a dark plumage, analogous to albinoism in other 

 birds. The examples cited are few in number, and not very conclusive, but 

 the subject is deserving of investigation. 



Many writers have written descriptive works on the eggs of birds, especially 

 of the European species. Of the older authors on this subject, as Klein, Wir- 

 sing, Sepp, Naumann, Schintz, Donovan, Roux, and Thienemann, I need not 

 here speak. In the ' British Oology' of Hewitson the eggs of our native 

 birds are accurately described and figured, and the second edition now pub- 

 lishing attests the popularity of the subject. An ' Atlas of Eggs of the Birds 

 of Europe' is just commenced by A. Lefevre at Paris, the figures of which 

 are well-executed. Of the eggs and nidification of exotic birds our informa- 

 tion is very incomplete, and almost the only contributor to this branch of 

 ornithology is M. D'Orbigny, who in his ' Voyage dans I'Amerique Meridio- 

 nale ' gives many figures of eggs and details of nidification, which may aid in 

 clearing up the affinities of certain doubtful forms of the South American 

 continent. 



Mr. Gould brought home from Australia a large and interesting collection 

 of eggs and nests, of which we may regret that he has not introduced the 

 figures into the plates of his ' Birds of Australia.' We may hope, however, 

 that when he has completed that great work he will publish an ' Australian 

 Oology,' and perpetuate the knowledge which his unique collection of eggs 

 supplies. 



Dr. Carlo Passerini has given an account of the nidification and incubation 

 of Paroaria cucullata in a domestic state, in a memoir published at Florence 

 in 1841. 



The subject of ornithic oology has been treated of in a philosophical man- 

 ner by M. DesMurs (Revue Zoologique, and Mag. de Zool., 1842-43). By 

 carefully studying the peculiarities of form, nature of shell and colour in the 

 eggs of various birds, he finds a correspondence between these peculiarities 

 and the structural characters of the several groups, and thus obtains an ad- 

 ditional element in the process of classification. 



The number of eggs laid by birds of different groups and species is the sub- 

 ject of a paper by M. Marcel de Serres (Ann. Sc. Nat., ser. 2. vol. xiii. p. 164), 

 and the author deduces some interesting generalizations upon this subject. 



There is a learned treatise on the structure of the egg prior to incubation 



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