56 Mr. W. Evans on the Periods 



of the Condor {Sarcorhamphus gryphus) is stated to be 54 

 days — an interesting record for the knowledge o£ which I am 

 indebted to Professor Newton. In the ' Encyclopaedia Britan- 

 nica ' (9th ed. vi. p. 253) the period assigned to this bird is 

 seven weeks^ which does not differ very materially from that 

 given by Broderip. 



The ' Zoologist '' for 1881 (p. 106) contains what appears 

 to be a reliable record of the hatching of three eggs of the 

 Common Buzzard {Biiteo vulgaris) by a tame bird of the 

 same species. Incubation is said to have lasted 31 days. 



From Dr. Giglioli's ' Primo Resoconto dei Risultati della 

 Inchiesta Ornitologica in Italia/ to which Messrs. Eagle 

 Clarke and Harvie-Brown have kindly drawn my attention, 

 it appears that the duration of incubation was one of the 

 points upon which the array of observers who make returns 

 to the " Ufficio Ornitologico " were asked to report. This 

 elicited from several of the observers a series of statements 

 which will be found in their reports, as recently pub- 

 lished by the Italian Government in the second part of the 

 above-mentioned work. A careful analysis of these state- 

 ments and a comparison of them with ascertained facts shake 

 my confidence in the accuracy of the bulk of them, and make 

 me doubt whether, as a whole, they are of any real 

 value. What seem to me to be manifest inconsistencies 

 and contradictions present themselves at every turn. For 

 instance, according to the table (p. 13) furnished by one 

 observer, the period is the same, namely 16 to 18 days, for 

 the Siskin, the Tawny Owl, the Stone Curlew, &c. Another 

 observer gives (p. 187) 8 days for the Cirl Bunting and 10 for 

 the Larks ; while a third tells us (p. 354) that Larks, Finches, 

 and Buntings incubate 15 to 20 days. At p. 190 the Land 

 Bail's period is set down at 12 days, and on p. 228 at 20-22 

 days. In the case of several of the Partridges, the Black 

 Grouse, and the Ptarmigan, incubation is said to last from 18 

 to 20 days, an understatement, as it seems to me, of about 5 

 days. Again, is it possible that eggs of the Bearded Vulture 

 {Gypaetus barbatus) can be hatched in ''about 20 days" 

 (pt. 1, p, 420.)? Many other difficulties might be pointed 



