324 Recenthj published Ornitholoyical Works. [Ibis, 



Shrikes, and many otlier families may be quoted as be- 

 longing to the former. Some of the communal breeders 

 have also adopted a system of eommunal defence (more 

 especially the Terns), but with others nothing of the kind 

 has yet been evolved. 



We think a truer idea of Territory in Bird Life would be 

 gained by eliminating the actual nesting-site, which is, 

 of course, a necessity in every case, and restricting the 

 use of the word to the area embraced l)y the activities of 

 the parents. We shall then find that in some groups all 

 otlier individuals of the same species are rigidly driven off 

 the whole territory, in others the idea is only present in a 

 rudimentary form, and in a third class the association is of 

 the closest kind and individual territory is unknown. 



There is also a wide field for research, untouched in the 

 present work, on the occasional unresented presence of a 

 third individual together with a pair in the case of a nor- 

 mally monogamous species. Probably this has been noted 

 most frequently in the case of the Long-tailed Tit, but 

 there are recorded instances in some twelve or fourteen 

 other species at least. We are grateful to Mr. Howard for 

 his beautifully illustrated and thoughtful study on an aspect 

 of bird-life, which by his researches he has undoubtedly 

 done much to elucidate. — F. C. R. Jourdain. 



Hellmayrs recent papers on Neotropical Birds. 



[Ein Beitrag zur Ornithologie von Slidost-Perii. Vou C. E. Hellmayr. 

 Arch. Naturgesch. Jahrg. 85, Abt. A, 1920, pp. 1-131.] 



[Miscellanea Ornithologica, V. Id. Verhandl. Orn. Ges. Bayerii, 

 xiv. 1920, pp. 281-287.] 



The first of these pa])ers contains an account of the more 

 interesting forms contained in a collection made by the 

 brothers H. and C. Watkins in the Department of Puno 

 in south-eastern Peru, near the Bolivian border. These col- 

 lections reached Europe before the outbreak of the war, 

 and are now preserved, partly in the Munich Museum, 

 partly in the private collection of Count Josef Seilern. 



