FALCONIDAE. 



with those which are often found on eggs of Conv/s-species, and 

 which probably consist of bililiumin, a blacl<, insoluble, very strongly 

 oxidized substance. ') 



In tinniincuhis as well as in subbuteo striking mutual differences 

 in colour and markings occur between eggs of one and the same set. 



n See: Dr. A. A. Mc. Aldowie, Observations on the development and the 

 decay of the pigment layer on bird's eggs. (The Journal of anatomy and 

 physiology, Vol. XX, I88C). 



