IV 



of each form has been measured by the writer, or statistics compiled from 

 thoroughly reliable sources. The weight, though a very variable factor, is 

 useful in combination with statistics of size, and its value has been under- 

 rated by English naturalists. In this connection Gobel's tables in the 

 Zeitschr. f. Ool. are important, though unfortunately misprints are not 

 unknown. At present the statistics on the weight of the full egg are too 

 scanty for us to estimate their value. 



It is with much pleasure that the author is able to announce that 

 arrangements have been made to figure thoroughly identified specimens of 

 many rare eggs. Among these we may mention Whitehead s Nuthatch, 

 Riippell's Warbler, La Marmora's Warbler, the Knot, etc. 



Addenda et Corrigenda to Part I. 



p. 5. C. corax laurencei Hume has been shown by 0. Reiser {Ornis Bal- 

 canica, III, p. 255) to occur in the eastern part of the Greek archipelogo. 



p. 20. P. pica mauritanica Malh. The breeding season extends from 

 March to May. 



p. 23. Nucifraga caryocatactes (L.). Reiser has recorded a single 

 clutch of 5 eggs from Bosnia, Mar. 22, 1904 {Zeitschr. f. Ool. 1904, p. 13). 

 For notes on the nesting of this bird in Hungary see Aquila 1894, p. 48. 



p. 31, 1. 11 from below. For 'Sicily' read 'Brittany'. In Sicily the 

 Chough only breeds on the mountains inland. 



