They could be noted like little specks against the blue sky, gradually growing larger and larger, until their broad wings cast moving shadows upon the sunlit sward, as the birds floated spirally downward.

Others were observed approaching in a horizontal direction-- some of them seeming no bigger than sparrows, as they first caught the eye upon the distant horizon.
"What a distance some of them must have travelled!" remarked Francois; "and how do you think they know where to come?
There was not one in sight when we killed those big-horns." "They have been guided by their scent, of course," replied Basil; "they have great power in that way." "Not so, brother," interrupted Lucien; "that is one of the errors of your closet-naturalists--your Buffons and Cuviers--propagated by them, until it has become proverbial.

Strange to say, it is altogether erroneous.

It has been proved that vultures possess the sense of smell in a less degree even than most other creatures.

Dogs and wolves far excel them in this respect." "How, then, have they found this carrion, for instance ?" "By their sight--for that sense they possess in a high degree of perfection." "But how can that be, Luce ?" rejoined Basil.