520 PLINY'S NATURAL HISTOET. [Book X. 



sieging army ? his nets, too, which he had spread in the river, 

 while the messenger of the besieged was cleaving the air ? 



Many persons have quite a mania for pigeons huilding towns 

 for them on the top of their roofs, and taking a pleasure in 

 relating the pedigree and noble origin of each. Of this there 

 is an ancient instance that is very remarkable ; L. Axius, a 

 Eoman of the equestrian order, shortly before the Civil War of 

 Pompeius, sold a single pair for four hundred denarii, as welearn 

 from the writings of M. Yarro. 58 Countries even have gained 

 renown for their pigeons ; it is thought that those of Campania 

 attain the largest size. 



CHAP. 54. (38.) DIFFERENT MODES OF FLIGHT AND PROGRES- 

 SION IN BIRDS. 



The flight of the pigeon also leads me to consider that of 

 other birds as well. All other animals have one determinate 

 mode of progression, which in every kind is always the same ; 

 it is birds alone that have two modes of moving the one on 

 the ground, the other in the air. Some of them walk, such 

 as the crow, for instance ; some hop, as the sparrow and the 

 blackbird ; some, again, run, as the partridge and the woodhen ; 

 while others throw one foot before the other, the stork and the 

 crane, for instance. Then again, in their flight, some birds ex- 

 pand their wings, and, poising themselves in the air, only move 

 them from time to time ; others move them more frequently, 

 but then only at the extremities ; while others expand them 

 so as to expose the whole of the side. On the other hand, 

 some fly with the greater part of the wings kept close to 

 the side ; and some, after striking the air once, others twice, 

 make their way through it, as though pressing upon it enclosed 

 beneath their wings ; other birds dart aloft in a vertical di- 

 rection, others horizontally, and others come falling straight 

 downwards. You would almost think that some had been 

 hurled upwards with a violent effort, and that others, again, haoL 

 fallen straight down from aloft ; while others are seen to spring 

 forward in their flight. Ducks alone, and the other birds of 

 that kind, in an instant raise themselves aloft, taking a spring 

 from the spot where they stand straight upwards towards the 

 heavens ; and this they can do from out of the water even ; 

 hence it is that they are the only birds that can make their 

 5 <> B. iii. c. 7. 



