FALCONIDAE. 



Dresser's opinion ') that spots which cannot he washed off are 

 pigment spots, I do not share, as it is quite possible for substances 

 originating from nest-material etc. to penetrate into the eggshell and 

 for it to be impossible to remove the same. 



The so-called „greasc-spots" („Oeltropfenflecke" of German 

 writers) which Dr. R. Baron von K(')N1Q — Warthausen -) takes to 

 be „stellenweise Steigerung des Grundtons", therefore a local accumu- 

 lation of oocyanin in layer I, or a diminution of carbonate of lime 

 in layer II, appear to me, on examination, to be attributable to a 

 local accumulation of glutinous substance in layer I. 



ACCIPITER NISUS (L.). 



The very variable markings of these eggs consist either of a few, 

 frequently large, spots, forming an irregular zone low down on the 

 basal end or near the bellied portion of the eggshell, or of clouds 

 and smears covering almost the whole surface, often accompanied 

 by coarser or finer specks and veins. 



As a striking peculiarity of «/s(;s-eggs, 1 find it stated that one 

 side of them is sometimes marked very strongly, the other side, on 

 the other hand, being marked particularly little. This phenomenon 

 I have however found to be one of general occurrence in the case 

 of irregularly spotted eggs. 



I am able to confirm from my own experience that the eggs which 

 are laid last are coloured sea green more strongly than the other 

 eggs, and sometimes exhibit lighter tinted spots; and R. Kearton 

 also says to have observed that of sets of six eggs the markings 

 of two are always fainter than those of the other four eggs. 



1) L. c, parts III— IV, page 69. 



^) Ueber die zur Unterscheidung der Vogclcier dieiiendeii Mcrkmalc (Wiirtemb. 

 nafurw. Jahreshefte, 1876.) 



