6o 



The Bird 



verge more and more, until two distinct longitudinal 

 lines are formed, with traces of a third near the quill. 

 A smaller feather from the same wing is marked with 

 spots which are nearly circular and which show faint 

 traces of encircling bands of white pointing toward a 

 still more elaborate system of decoration. 



Fig. 39.— Evolution of a colour pattern upon two feathers of a ultunne Ciuirea- 

 fovvl; a stripe breaking up into dots, these forming cross-vars, and on the 

 second feather a regular series of dots encircled with white. 



It is interesting to conjecture in which direction the 

 decoration of feathers is proceeding. In the case of the 

 guinea-fowl, are the spots converging into lines or are 

 the lines the more ancient, and for some reason grad- 

 ually splitting up into smaller divisions? This is hard to 

 decipher, and if we look at the rest of the guinea-fowl's 

 body, the matter becomes only the more complicated. 



