THROUGH WILD EUROPE 133 



many nests. His description of what he observed 

 exactly corresponded in every particular with what I 

 saw myself as described above. 



The old birds frequently yawned, stretching their 

 necks and beaks upright, at the same time arching 

 their lower mandibles, which are exceedingly flexible, 

 into the shape of a hoop. It may be perhaps that 

 this is an attempt to dislodge the numbers of 

 parasites, like intestinal worms, which adhere in 

 large numbers to the inside of the pouch. Large 

 bunches of these worms were found inside the 

 pouch of an adult female which was shot and 

 skinned. 



The peculiar character of the skin was very 

 noticeable. It was porous and cellular to an extra- 

 ordinary degree, resembling nothing so much as a 

 series of innumerable air bubbles. Even the body 

 had large air cavities, and the bones were very 

 hollow. This porosity no doubt helps to support 

 their huge bodies in the air, and so must serve a 

 most useful purpose during flight. They fly well 

 and strongly, with the head drawn back and the 

 beak resting on the doubled-back neck. 



This colony had its parasites in the shape of 

 Hooded Crows (Corvus comix) and Gulls (Larus 

 cachinnans) which walked about among their huge 

 hosts in a most familiar, not to say impudent 

 manner. They no doubt act as scavengers, and 



