147 [Vol. xli. 



clutch of six typical eggs, also a clutch of six exceptionally- 

 handsome eggs, heavily blotched with rich dark brown, mostly 

 confined to the large ends, both from Spain, April 19 and 

 26, 1907. 



Lesser Grey Shrike (Lanius minor). These remarkably 

 handsome eggs were well represented by thirteen typical 

 clutches, some of which were very boldly blotched, mostly 

 from E,oumania. 



Red-backed Shrike (Lanius collurio). A series of one 

 hundred clutches, from which repetition had been carefully 

 eliminated; these were divided into two types, showing the 

 extreme and modified forms of each. 



Mr. Bunyard then made the following remarks on them : — 



The eggs of the Red-backed Shrike {Lanius collurio) have 

 oologically highly specialized characteristics, and cannot be 

 confused with those of any other British breeding-bird", the 

 marked variation in the ground-colour and arrangement of 

 the pigmentation equals in many respects those of the Tree- 

 Pipit (A. trii'ialis). Two types appear to be constant — those 

 with the whitish to greenish ground-colour and those with 

 the cream to reddish ground. These occur in about equal 

 proportions, though it is sometimes stated on very meagre 

 evidence that in certain localities one of the two types pre- 

 dominate. Age undoubtedly has some influence on pigmen- 

 tation, and if certain local climatic conditions have any 

 influence on food-supplies, then I must admit the highly 

 probable influence that food may have on pigmenta- 

 tion. I have proved beyond doubt that there is no 

 transition in a single season, i, e., the same female will, if 

 nests are systematically taken, produce the same type up to 

 as many as three to five clutches. 



Lechner * — in my opinion, rightly — assumes that certain 

 individuals belong to oologically differentiated tribes, each 

 having its own type of egg, which, of course, must not be 

 confused with varieties, as each type has the extreme and 

 modified forms. This is, I think, generally admitted to be 



* ' Oologia Neeiiandica,' A. A. van Pelt Lechner. 



