776 REPORT—1899. 
The Soft Tissues.—The gelatinous layer, above alluded to as investing the 
ridges of the skeleton, lines the openings of the canal system and extends as a 
sheet, thin in the centre, over the mouth of each canal. A round pore is frequently 
present at this point, but in many cases the membrane is not perforated; the 
spaces at the mouths of the canals are, however, in communication with one 
another by lateral channels through the jelly, beneath the surface membrane. 
Besides the cells in which the spherules are found, there are branched amceboid 
cells sparsely scattered through the jelly. 
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CILIATED CHAMBERS 
CANAL 
Section of soft tissue (highly magnified), 
The soft tissues of the sponge are contained in the skeletal canals (as they may 
now be termed to distinguish them from the canals which run in the soft parts), 
and penetrated by the water-bearing canals which open by the pores at the surface. 
From the main canals small ones are given off which ramify in the layer cf soft 
tissue in contact with the skeleton. 
As the canals are followed downwards into the interior, the cellular elements 
in their walls, at first scattered, become more and more abundant, and the jelly 
legs conspicuous, Ata short distance from the surface the soft tissue assumes the 
