Sex Dimorphism and Variability in the Appendicular Skeleton of the Leghorn Fowl

During the past five years there has been sent to this department a number of male fowls suspected by their owners of having been originally females and of having turned into functional males in a manner similar to that of the cases described in the fowl by Crew5 and in the pigeon by Riddle.17 In nearly every instance it has been impossible to verify the accuracy of the case history by breeding tests or by post mortem examination. Sex dimorphism, in size as well as in plumage and colour, is more conspicuous in the Gallinae than in the majority of other birds. It seemed possible that this dimorphism might be so great that skeletal measurements would give a clue to the original sex of such individuals as those mentioned above. It was recognized that the range in length of any single bone in one sex would probably overlap the range . . .