796 [ Assembly 
translucent; and the whole back would become highly inflamed and 
sore, scabbing over and peeling off, bringing the wool wiih it and leav¬ 
ing the surface bare. Greasing the backs with lard was the practice 
to mitigate and cure this ; but the better plan was to prevent it, which 
was effected by blanketing the lambs. A little experience enabled one 
readily to recognise these peculiar thin wools and tender skins as soon 
as they were born, and it was the practice of some, into whose flocks 
they became introduced, to sew on to them a piece of woolen or cotton 
cloth so securely that it would remain about a fortnight, by which lime 
the back would become sufficiently tough to withstand the rays of the 
sun. Full grown thin-wooled Saxons after shearing are also liable to 
have their backs become burnt and excoriated by the sun in a similar 
manner ; and to prevent this it is necessary that they should be anoint¬ 
ed in the same mode at shearing time. 
159. The sheep-tick. By some popular writers this insect has been 
supposed to be a true lick, of the old genus Acarus, and we hence meet 
with it in books, referred to as being the Acarus reduvius of naturalists, 
a tick which infests cattle and dogs. It is probable that by the common 
name of this insect and by the circumstance that it does not possess 
wings, these writers have been misled to refer it to a place very far 
from where it really belongs. This mistake requires correction. The 
true ticks and mites have eight legs, like the spiders, with which they 
are accordingly classed in systematic works. This insect, however, has 
six legs only, and consequently belongs among the true insects. 
At the close of the two-winged flies which constitute the order Dip- 
tera, is placed by naturalists, a small group named HippobosciDjE, the 
subjects of which constitute a connecting link between the true insects 
and the spiders, i hey have such a striking resemblance to spiders, 
that they are known in some countries by the name of “ spider-flies.” 
They differ from all other flies, notably, in some points of their organi¬ 
zation, and in their habits. Though furnished with wings, it is seldom 
if ever, that they use them, for they do not fly abroad like the other in¬ 
sects of this order, but are parasites, passing their lives upon particular 
quadrupeds and birds. By means of the forked claws with which their 
feet are furnished, they are able to cling securely to the hair or feathers 
of these animals, and to run about among them with rapidity, and also, 
to fasten themselves to the skin, piercing £it with a sucker, through 
which they receive their nourishment. 
several of these flies are found upon the animals belonging to this 
continent. If an owl is killed in mid-winter, there will sometimes be 
discovered wandering about upon its feathers, or in the vicinity where 
its body is laid, a fly, which is the more observed from its being- abroad 
