SPONGES 19 
The buds sometime form directly from the body of a cylinder or at some 
distance from it through the spreading out of a comparatively thin portion of 
the sponge over any material upon which it grows. 
In the Tube Sponge eccentric budding occasionally takes place, that is, 
the buds sometimes haye their origin above the base, but in such instances, we 
Fig. 10. 
[G 
Water system of Tube Spoae. Allen's Skeleton of Aplysina gigan- 
Harbor. May, 1693. Enlarged. tea, Bahamas, 1893, life size. 
find that the large central tube (see Fig. 7, 0, 0, ) hasbeen stopped up or 
partly filled with sand or some other material, or the walls have become 
broken through, hence the base of the sponge has practicably been changed 
toa higher level. Such accidents, however, are comparatively rare, and 
thus any variatien from actual budding at the base, either on or near a 
cylinder is rare. | One of what is the most extreme departures from this rule 
occurs on a single cylinder seven inches high, the bud appearing about 
