98 Maddox,, on Acari in a Nitrate of Silver Bath. 
treating them to these baths, and finally washing them, the 
general structure was rendered very visible under the micro- 
scope, though still very fatty in appearance. Wishing to pre- 
serve some of the specimens, I proceeded to put them upon the 
slides — first trying washing in spirits of wine, then drying, 
soaking in turpentine, and setting up in Canada balsam diluted 
with benzole. I could not set them out in this, as the parts 
gave way very readily, from the tenacity of the balsam, and 
portions were rendered too transparent. Others were first 
cleared of the deposit, soaked in glycerine and camphor 
water, and finally mounted in the glycerine and gelatine- 
m£dium ; this proved the most successful, though I found 
that they still so retained their fatty quality that I dared not 
use sufficient pressure to flatten out their rotund bodies, ere 
the skin gave way. They gave me considerable trouble, 
although long accustomed to put up objects of various kinds. 
Further observation led to the opinion of their being Acari, 
though not like any I was acquainted with. 
The insects are quite visible to the unaided eye, being a 
little larger than the cheese-mite. They are variable in size. 
The sexes are evident, the females being provided with a 
curious short protuberance or tubercle at the end of the 
abdomen, nearer the upper surface ; and at a slight distance 
from it, on the under surface, when seen sideways, are two 
thin projecting flaps wliich meet at the free edges, thus 
forming a sort of deep and long triangular space, sack, or 
groove, protected at the anterior entrance with a few short 
crossing hairs. Looking down on this structure it has 
an elliptical form : the edge of each flap has from four to 
six reddish marks (glands or booklets of apposition?) In 
this pouch I was fortunate enough to find a body sus- 
Surface of body covered with minute sharp points. 
pended, which I considered to be an extruded ovum. 
Pressure in several cases, especially after the use of the 
