SPONGES Oo” 
visited the Bahamas occurredin August, 1892, and this was not specially 
severe. If they were broken by the waves of that gale, they had eight months 
in which to repair damages, and they may have been broken during a previous 
season. Why the new sarcode deposited over the broken ends of the cylinder 
did not produce a new growth of fiber, independent of the old growth, as we 
have seen that it does when a new partition has formed across the central tube, 
and what the ultimate fate of these broken cylinders is, it is dithcult to state. 
As I have never found any buds starting from their base. nor any larger 
growth about them, it is probable that these broken sponges being unable to 
entirely overcome the shock which they have sustained, are leading a kind of 
life in death existence, and that after lingering for a comparatively short time, 
die. | 
We have seen that abnormal conditions of growth appear to occur in the 
tube sponge when it is attacked by parasitical sponges. = J cut off'a portion of 
the specimen of which I have spoken on page 21 as having been attacked by a 
parasitical sponge of the spiculigenous group (the Purple Sponge, Pachycha- 
lina rubens ), where the intruding species had come in contact with the skele- 
ton, and upon examining it, found that many of the fibers are apparently ina 
diseased condition and present abnormal growths. They are enlarged in places 
by a whitish accumulation of a substance which appears to arise directly from 
the horny covering of the fiber and to form a part of it. Such examples are 
givenin Fig. 15, A and B. - There is also a great tendency to produce abor- 
tive twigs, often in terminal tufts. | 
We find this tendency to produce abortive twigs in the srotuberances on 
‘the sides of aged and much roughened sponges.: In these we also find a kind 
of secondary growth in the form of fine new twigs, which appear to be filling 
the cavities between the projections, thus thickening the wall+ ot the sponges. 
