302 TROPICAL WILD LIFE IN BRITISH GUIANA 



Photo by P. G. U. 

 FIG. 99. CLAWS OF THJIEE-DAY-OLD JACANA SHOWING CURVATURE 



Innately provided with shorter toes. Thus a useful tend- 

 ency was fostered and, through long past ages of gradual 

 selection, the lengthened toes slowly evolved. 



SPUBS 



Quoting from Forbes, we find that: "The 'spur' in Par- 

 ra jacana at least, consists of an external, translucent, yellow 



