ON TRACHEAN ARACHNIDA. 
531 
The sexual intercourse of these mites takes place in the 
same manner as that of other insects. The female lays some 
oval eggs, very white, and which appear to be reticulated or 
spotted with brown. 
Leuwenlioek,who has particularly observed this species, saw 
but six feet upon the little ones just disclosed; and the same 
has been remarked in relation to the mite of the itch . Pro- 
pagation goes on even in winter, at least in our houses, the 
temperature which reigns there being favourable to the activity 
of these little animals. 
Acarus farince, Deg. (the mite in flour), is elongated, white, 
with the anterior part reddish, and advanced in the form of a 
thick and conical muzzle. The eight feet are thick, and 
tolerably long, especially those of the first two pair. The 
body also has hairs, and those of the hinder part arc very long. 
Degeer could not perceive at the extremity of the feet the 
vesicle which we have mentioned belonging to the feet of the 
preceding species. These animals walk tolerably fast. 
Linnaeus at first distinguished separately the mite of the 
itch , but he subsequently confounded it with the two preced- 
ing species. 
“The mites,” says Degeer, “which I had occasion to ex- 
tract from the ulcers of the itch, were very small, and not 
larger than grains of ordinary sand. The colour of the body 
is white, and transparent; but the head and feet have a slight 
tinge of red or yellowish brown. The body is of a rounded or 
almost circular figure, and its surface is rugged, having ine- 
qualities, and here and there some hairs, but in small quanti- 
ties. The head is in the form of a muzzle, short, cylindrical, 
rounded at the end, and furnished with some hairs ; but the 
smallness of the insect prevented me from detecting its parts, 
and ascertaining their true construction. Not having been 
able to remark upon the back two curved brown lines of which 
Linnaeus speaks, I have reason to believe that the mite of which 
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