By the Rev. A. C. Smith. 245 
than any other family: it seems that this faculty is given them in 
common with other nocturnal and crepuscular animals; as, for 
example the bats, to enable them to guide themselves in their flight 
on the darkest nights, and to direct them to their prey: the organs 
with which they are furnished to secure this endare of a very re- 
markable construction, and developed to an extraordinary extent: 
the auditory opening, or ear-couch, is sometimes extremely large, 
and is then furnished with an operculum or cover, which they can 
open and close at will: but in those species where the aperture is 
smaller, such an addition is not provided. Another peculiarity in 
the nocturnal birds of prey is that the two ears are not alike: the 
one being so formed as to hear sounds from below, the other from 
above: this though an old discovery, is not very generally known; 
though it is doubtless an admirable help to catch the faintest sound 
proceeding from every direction; and with such organs the owls 
are enabled to detect in an instant the slightest rustling of their 
prey. Next to the owl, perhaps the night-jar (or goat-sucker, as it 
is commonly though erroneously called) possesses the most acute 
sense of hearing: this bird is also crepuscular, and seldom hunts 
for moths till the shades of evening; and, as in the owl, its ears 
are of very large size. But there are many other birds gifted with 
remarkably acute powers of hearing: see the song-thrush descend 
on the lawn on a damp morning; watch how he inclines his ear on 
one side, then hops forwards, and again listens, till at length he draws 
forth the worm which his fine ear had told him was there, and which 
alarmed at his hops and peckings had hurried to the surface, sup- 
posing they were occasioned by his dreaded enemy, the mole: or 
visit some fine old heronry, and try to penetrate near their chosen 
nursery without your presence being detected: these nocturnal birds 
are not particularly keen of sight during the day, but long ere you 
can approach them, however cautiously, their keen sense of hearing 
has told them youarenear. Another bird remarkable for possessing 
this faculty in an eminent degree, is the curlew: of all the shore 
birds there is not one so difficult of approach as this: his organs of 
hearing are so sensitive, that it is almost impossible to come near 
him: and again, the Swedish ornithologist, Professor Nilsson, 
