WHITE-FACED IBIS 119 



a much larger number. It is most interesting to 

 watch them at such times, now soaring high in the 

 air, displaying the deep chestnut hue of their breasts, 

 then descending with a graceful curve towards the 

 earth, as if to exhibit the dark metallic green and 

 purple reflections of their upper plumage. The flock 

 is meanwhile continually changing its form or dis- 

 position, as if at the signal of a leader. One moment 

 it spreads out in a long straight line ; suddenly the 

 birds scatter in disorder, or throw themselves together 

 like a cloud of Starlings ; as suddenly they re-form 

 to continue their journey in the figure of a phalanx, 

 half-moon, or triangle. The fanciful notion can 

 scarcely fail to suggest itself to the spectator that 

 the birds go through these unnecessary evolutions 

 intelligently in order to attain a greater proficiency 

 in them by practice, or, perhaps, merely to make a 

 display of their aerial accomplishments. The Glossy 

 Ibis has another remarkable habit when on the wing. 

 At times the flock appears as if suddenly seised with 

 frenzy or panic, every bird rushing wildly away from 

 its fellows, and descending with a violent zig-zag 

 flight ; in a few moments the mad fit leaves them, 

 they rise again, reassemble in the air, and resume 

 their journey* 



