JUNE 
197 
molest man in the open clearing in this country^ except in 
one instance ; in which one of the little Clouded Whameflies 
( Chrysops Sepulchralis ? J suddenly darted at the hand of 
my brother three successive times without alighting, inflict- 
ing a wound each time : it left hard whitish lumps^ attended 
by severe pain. The mouth of these insects is a fine piece 
of mechanism : a fleshy case contains two spiny serrated 
needles^ and two broad lancets, shaped like a knife, working 
laterally ; these are to cut and enlarge the wound, and in- 
crease the flow of blood ; within these is a fine tube enclosed 
in a separate sheath, through which the blood, probably di^ 
luted by some injected fluid (which causes the inflammation 
and pain) is sucked into the stomach. The palpi are short, 
straight, and fleshy, and being situated one on each side of 
the proboscis, guide and guard it from injury while piercing 
an animal. The whole apparatus, being little larger than the 
point of a pin, is well worthy of regard and admiration. I 
have taken the larger species from my horses, so full of blood, 
that the abdomen was swollen almost to bursting, and of a 
deep red colour. It appears that on such occasions, as well 
as in musquitoes, ticks, &c. the vessels and intestines must 
be either disruptured, the blood flowing among the whole 
viscera, or else capable of such enormous distension, as almost 
to fill the whole body. That the bodies of some insects are 
capable of very great enlargement, is proved by the Chigoe 
of the West Indies f Pulex Penetrans ), the White Ant of 
Africa ( Termes Fatale J, and many species of tick. I have 
myself often seen in the Southern States, Ticks f Acarus 
Americanus ) which, in their natural state, were not more 
than one eighth of an inch in diameter, and no thicker than 
writing-paper, swollen to the diameter of half an inch, and 
the thickness of an eighth of an inch, merely by the blood 
sucked from the body of some animal. 
C — The Golden-eyed Pearl-fly ( Hemerohius Perla ) is 
