ATAVISM IN GUINEA-CHICKEN HYBRIDS 
BY 
MICHAEL F. GUYER 
University of Cincinnati ' 
(Witn Four Pirates) 
In 1905 the writer came into possession of five adult hybrids 
which had been produced by crossing a cock of the black langshan 
breed of chickens with an ordinary domestic guinea-hen. ‘The 
present paper is concerned chiefly with a curious color pattern 
which manifested itself in these fowls. It is unlike anything in the 
coloration of either parent and is to all appearances atavistic in 
nature. 
Concerning the immediate ancestry of the five hybrids, little 
need be said as both are common domestic fowls. 
The guinea (Fig. 1, Plate I) is of clumsy build and weighs only 
about three and one-half pounds. It is remarkable for the yellow- 
ish or brownish bony helmet which surmounts its naked head. 
Its neck is also naked except for a few bristle-like feathers which 
form a median row up the back and which may also in some indi- 
viduals be sparsely scattered along the sides and front. A median 
longitudinal fold of skin under the throat is more or less developed 
in most individuals. Broad, red gape-wattles are present and the 
cere and base of the beak are of reddish hue. ‘The sides of the 
face and upper neck are white with a decidedly bluish tinge. ‘The 
top of the beak is of orange color shading to light horn towards the 
tip which curves sharply downward. The neck, very small just 
1] wish to express my thanks for the many courtesies extended to me while at work in the Muséum 
d’Histoire Naturelle, Paris, and especially to record my appreciation of the kindnessof Professor E. Trou- 
essart, of the Department of Mammals and Birds, who has so generously put the resources of his Lab- 
oratory at my disposal. 
Tue JourNnat or ExPEeRIMENTAL ZOOLOGY, VOL. VII, NO. 4. 
