272 Letters, Extracts, and Notes. [Ibis, 



production, incidental and otherwise, of distinctiveness of 

 appearance in eggs of the same order. 



The resemblance referred to on line 37 of p. 36,2 is one of 

 rough general appearance. 



Yours truly, 

 Gungunjana, C. F. M. SwYNNERTON. 



Melsetter, Uliodesia. 



3 December, 1916. 



Sir, — It is rather misleading to class such birds as the 

 Lesser Black-backed and Herring-Gull as highly gregarious : 

 the Common Gull as less so, and the Great Black-backed as 

 least of all (p. 572). All these species are gregarious, but of 

 course the Great Black-back is much less numerous in the 

 Biitish Isles than the others. Even here there are colonies 

 where over fifty pairs breed together, and in Iceland I liave 

 known of over 1200 eggs taken from a single " hulm." 

 Mr. Swynnerton's statement that the eggs of the Great 

 Black-back are " rather markedly uniform" must be founded 

 on the comparison of a small or ill-selected series, for the 

 range of colouring, from spotless blue to red, is as great as 

 in the case of the Black-headed Gull. This is the more 

 remarkable as the number of eggs examined of the former 

 species bears no proportion to the countless thousands of 

 those of the latter which have passed under the eyes of 

 collectors. If only a limited number of the eggs of all our 

 British breeding species were examined, and in every case 

 the same number was available for comparison, the Black- 

 headed Gull would not be regarded as a species laying 

 variable eggs, but rather the reverse. 



Yours truly, 



H. 11. JOUHDAIN. 



Appleton llectoiy, 



Abingdon, Berkshire. 



15 January, 1917. 



