INTRODUCTION. 



Although the first number of this series of pamphlets was 

 announced to appear about the close of 1896, unavoidable cir- 

 cumstances retarded the work several months; but this delay 

 has not been without its beneficial results, for the time thus ex- 

 tended has enabled the author to gather much additional material 

 which has been of great value in the preparation of this paper. 



Over one hundred sets of eggs, each containing one or more 

 abnormal specimens, have been brought together along with the 

 copious notes appertaining thereto. Care has been taken to 

 incorporate in the paper only such notes as have been properly 

 authenticated and are based wholly on abnormal sets in the 

 author's possession. 



To my many ornithological friends who have kindly aided 

 me in this work, I wish to extend my sincere thanks, and earn- 

 estly solicit their fellowship and co-operation in the compila- 

 tion of future numbers. J. Warren Jacobs. 



Waynesburg, Pa. \ 

 Jan. 24, 1898. J 



