147 
LETTERS EROM ALABAMA. 
like a Musca^ but with a longer abdomen : the 
wings are dark brown with a purple gloss ; it is 
about an inch and three-fourths in length, and two 
inches and a half in spread of wing. Of its habits I 
know nothing, save that it is rather dull of motion. 
Not so a pretty Bee-fly [Bomhyliiis ?), 
which I caught this morning,— the first I have 
ever seen alive. I first discovered it by observing 
its shadow on the ground, quivering, yet stationary ; 
and on looking up, saw this pretty fly suspended 
in the air, about two feet from the ground, without 
any motion, except the rapid vibration of its 
almost invisible wings. What its object could be 
in thus suspending itself in the sunshine over the 
bare gravelled road, I am at a loss to conjecture. 
In general form it is much like a flesh-fly ; but it 
has a long straight proboscis projecting from the 
head, like that of a gnat. Its motions are very 
swift and sudden, shooting from one stationary 
point to another so rapidly as to be invisible 
during the transit. 
A singular instance of voracity, or of deviation 
from ordinary appetite, has come under my notice. 
I had found while out, a large downy caterpillar 
of the Tobacco Hawk-moth [Sphinx Carolina), 
and soon after, I took a stout dragon-fly [Lihellula 
?) . I put both into the same box to bring 
them home, and, on opening it, found that the 
caterpillar, having taken a fancy for a change of 
diet, had ventured upon animal-food, and had 
actually eaten a large piece out of his companion’s 
wing, including a good deal of the stiff and hard 
front rib : I should think he must have found it 
rather a dry dainty. I have occasionally before 
known a caterpillar to eat into the bowels of a 
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