8 



Wild Birds 



normally completing one term of the series before passing to the 

 next in sequence. The machinery, however, rarely works with 



Fig. 4. Cedar-bird at nest shown in Figs, i, 12, and 13, prepared to feed young 

 by regurgitation : a characteristic attitude. The parallel outlines of the neck 

 show that the gullet is full. 



absolute precision. Perturbations are sure to arise whenever 

 a contrary impulse comes into the field, and either blocks the 

 path or struggles for supremacy. 



