520 
pliny's katueal histoet. 
[Book X. 
sieging army ? his nets, too, whicli he had spread in the river, 
while the messenger of the besieged was cleaving the air ? 
Many persons have quite a mania for pigeons — building 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 we learn 
from the writings of M. Yarro.^ Countries even have gained 
renown for their pigeons ; it is thought that those of Campania 
attain the largest size. 
CHAP. 54. (38.) — DIFPEREITT MODES OF FLIGHT AND PEOGEES- . 
SION m BIEDS. 
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, had 
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 
58 B. iii. c. 7. 
