144 'Recently published Ornithological JVorhs. 



not attempt to introduce any new theories on tlie cause of 

 migration. Mr. Coward considers that fluctuating food- 

 supply, love of home, sexual impulses, desire for light, and 

 varying temperature have all been factors iu the migration 

 impulse. There are chapters on rontes, on the speed of 

 migrants' flight and the effects oi wind and weather, and on 

 early ideas and the history of the investigations. The book 

 contains, in fact, a good summary of our present knowledge 

 of this still mysterious problem. 



Hellmayr on Zonotrichia strigiceps. 



[Beinerknngen ueber eine wenig bekaniite neotropisclie Ammer 

 (Zonotricliia stri(jiceps). Von C. E. Ilellm.iyr, "\'erh. Oni. Ges. in 

 Bayern, xi. 2 Heft (1912).] 



The author writes a short history of Zonotrichia st7-i(/icej)S, 

 a rare South-American Finch, originally discovered by Darwin 

 and described by Gould. He also describes an allied form 

 as belonging to a new subspecies, and names it Zonotrichia 

 strigiceps dabbenei. It is from the mountains of north- 

 western Argentina. 



Hellmayr and v. Seilern on Venezuelan Birds. 



[Beitriige zur Ornithologie von Venezuela. Von C. E. Ilellmavr and 

 .T. Graf von Seilern. Arcb. f. Naturgesch. vol. Ixxviii. Abt. A, Heft 5, 

 1912, pp. 34-16G.] 



This paper is based on a collection of about 1200 skins 

 made by an American traveller, Mr. S. M. Klages, in 1909 

 and 1910 in northern Venezuela. The authors refer them to 

 171 species. They add the names of about twenty other 

 species that have been recorded as Venezuelan. 



The new subspecies described are Tangara (scribe Calliste) 

 guttata bogotensis, Myiodynastes chrysocephalus venezuelanus, 

 Pseudocolaptcs boissoneauti striaticeps, Sittasomus griseus 

 pirescens, Psammoplex brunnescens rosiratus, and Drymophila 

 CQudata klagesi. 



The Avork appears to have been most carefully done, as is 

 the case with other articles by Herr Hellmayr, but we protest 

 Ugainst his practice of adding the names of authors to 



