432 HT. James-Clark—The American Spongilla. 
Entering this aperture we do not meet with any obstacle 
for a little distance around it; there is a clear open space 
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Ow a power as two hundred diameters. We have studied 
these bodies with an 4th-inch objective, and found it not at all 
difficult to focus down upon the details of their organization, 
es, some 
outline ; or, when the whole mass is expanded, they scarcely 
impress eacli other, and therefore retain a rounded contour. 
By plunging the focus so as to look into the aperture of a cham- 
