34 Mr. C. G. Diivles 07i the 



above authors, but added anotlier species, viz, S. anderssonl, 

 adding, however, a note, of which the following is an 

 extract : — " .... But in stating our views it must be 

 admitted that the changes of plumage are so little under- 

 stood that it is quite possible that our conclusions will 

 require further modification ....■" 



Mr. Seebohm, in vol. v. of the Catalogue of Birds in the 

 British Museum, reduced the number of species to two, viz,, 

 S. leucomelcvna and S. monticola, with two subspecies, viz., 

 S. len cornel cena monticola and *S'. monticola Jeucomelcena ; but, 

 at the same time, propounded the theory that the two latter 

 might, as well as other forms, be caused through the inter- 

 breeding of the two species : he, however, fell into the error 

 of ascribing all the birds in grey plumage to the female sex, 

 in spite of the fact that many of the specimens examined by 

 him had been sexed by the collectors as males. 



In the volume of 'The Ibis' for 1883, p. 331, Messrs. 

 Butler, Feilden, and Reid wrote a long and interesting 

 article on this species, in which they gave their opinion that 

 from observations made in the field, and from a large series 

 of specimens collected by themselves in Natal, they had come 

 to the conclusion that there was only one species, viz. 

 S. monticola, which passed through a regular series of 

 plumage-chanues from black to grey. They illustrated this 

 theory by a list of nine plumage stagvs. 



Dr. E. B. Sharpe, in the same volume of ' The Ibis,' 

 wrote an article in wliich he, after having examined the 

 series of this species in the British Museum, came to the 

 conclusion that the theory of the above authors was the 

 correct one. 



In the volume of 'The Ibis ' for 1887, Mr. Seebohm, in 

 an article on Natal birds, while admitting that he had made 

 a mistake in the matter of the females, declined to admit 

 the correctness of the theory of Messrs, Butler, Feilden, and 

 Reid. He stated his reasons, and considered that, in his 

 ©pinion, the above authors had produced no proof, and still 

 adhered to his opinion that the different varieties were 

 caused bv interbreeding. 



