VoLXVIJ Recent Literature. 37 1 



for January, 1899, Mr. J. H. Gurnej has brought together a large amount 

 of authentic and interesting information on this subject, respecting 

 which it is so difficult to obtain satisfactory records. The first nine 

 pages of Mr. Gurney's valuable paper relate to the general subject, after 

 which the Passeres, the Psittaci, Striges, Accipitres, Pelecanida?, Ardeidae, 

 Anseres, and Diomedeidre are passed in review with reference to the 

 known facts regarding their longevity. Then follows a tabular state- 

 ment of 144 cases, representing 75 species, giving the age and the authority 

 for the record, with finally some comparison between the longevity of 

 birds and mammals, and suggestions as to the points on which further 

 information is needed. Prom the table it would appear that Thrushes 

 live from 15 to 20 or more years (there is a record for the Nightingale of 

 25) ; Finches, from 14 to 23 years; Ravens (two cases), 50 and 69; Mag- 

 pies and Crows, 17 to 28; Parrots and Macaws, 17 to So; Owls, 18 to 6S ; 

 Eagles, 20 to 56, etc. A domestic Goose has a record of So years, and a 

 Collared Dove (Turtur risorius) of 40. These cases, of course, nearly all 

 relate necessarily to birds held in captivity or in domestication, and 

 hence living under more or less artificial conditions. These conditions 

 we know are often unfavorable to the well-being of the captive, while, on 

 the other hand, they may be exceptionally favorable to long life, in par- 

 ticular cases. On the whole, it is to be presumed, however, that a bird's 

 chances for long life are rather better in a state of nature than in cap- 

 tivity, excluding the domesticated kinds. 



This interesting subject has received further attention at the hands of 

 Dr. Gill, who has not only reprinted Mr. Gurney's paper entire, "with 

 some revision," in ' The Osprey ' for June, 1S99, but follows it with a long 

 article of his own, entitled 'The Longevity of Birds and other Verte- 

 brates.' * Dr. Gill considers the subject from the historical and theoretical 

 side, in relation to certain hypotheses for determining the life of an 

 animal, held by various authors, from Buffon and Flourens to Hollis and 

 Bell, by the latter of whom the matter has been recently discussed in 

 'Nature' (January, March, and May of the present year). These 

 hypotheses are based on the period of gestation, or of adolescence. Dr. 

 Gill believes that there is an inherent fallacy in all the 'laws' thus far 

 proposed, and that a rule which may hold good for some members or 

 groups of a class will not admit of universal application for the whole 

 class, and much less for all vertebrates. " It is evident," he says, " that 

 there are no such ratios between the size of a bird and its duration of 

 life, its period of embryological development, and its period of adoles- 

 cence as prevail among mammals. Nevertheless, there are indications 

 that there is a tendency at least towards an extension of the duration of 

 life among some large birds, as those of prey, and towards the retarda- 

 tion of the development of the livery of perfect maturity. Even this, 



14 The Osprey,' Vol. Ill, June, 1899, pp. 157-160. 



