VISION. 231 
low. During their evolutions on such occasions, 
the dense mass which they form exhibits a beau- 
tiful appearance as it changes its direction, now dis- 
playing a glistening sheet of azure, when the backs 
of the birds come simultaneously into view, and 
anon suddenly presenting a mass of rich, deep pur- 
ple. ‘They then pass lower over the woods, and for 
a moment are lost in the foliage, but again emerge 
and are seen gliding aloft.” 
The return of the carrier pigeon from such dis- 
tances to its home is, we think, most plausibly ac- 
counted for by its flying in circles; but that there 
may be some other manner in which it is directed, 
is not improbable from what takes place among 
quadrupeds. Instances, for example, are not un- 
common of cats having returned of their own ac- 
cord to the place from which they have been car- 
ried, though at the distance of many miles, and even 
across rivers, where they could not possibly have 
had any knowledge either of the road or of the direc- 
tion that would lead them to it. “The nature of 
this beast,” says Gesner, “is to love the place of 
its breeding ; neither will she tarry in any strange 
place, although carried far, being never willing to 
forsake the house for the love of any man, and most 
contrary to the nature of a dog, who will travel 
abroad with his master: but although their masters 
forsake their houses, yet will not these beasts (cats) 
bear them company; and, being carried forth in close 
baskets or sacks, they will return again.”* We have 
thus known a cat to travel from London to Chat- 
ham in Kent, a distance of thirty miles; and most 
persons can relate similar incidents. Gesner, how- 
ever, is not correct in confining this propensity to 
the cat, for dogs frequently do the same. D’Obson- 
ville, in his curious work, mentions a remarkable in- 
stance in a mastiff. This dog, which he had brought 
* History of four-footed Beasts, by Topsel, p. 82. 
