236 Proceedings of the Royal Physical Society, 
and description of each. I am really very much indebted to 
Dr Fleming for his kind assistance, and sincerely wish I 
could in conscience support his Gydonium to the exclusion 
of Geodia. Present my respects to him." In February 
1856, Dr Bowerbank says, " I have just received such a 
glorious box of sponges from Western Australia, radiant 
with colour, purple, rose, cream, and all sorts of tints, and 
full of fleshy matter. There are forty-four grand specimens, 
some eighteen inches high, but when shall I get to work on 
them ! I am overwhelmed with material, having received 
advice of another large collection of sponges and corals from 
Madeira, w^hich are on their way. I think I must take 
Finsbury Square by-and-by, or I shall have no chance of 
exhibiting them. I am glad you and I agree so well re- 
garding the arrangement of the Spongiadce. It is quite 
delightful to have some one like yourself to write to about 
them, all the rest of the world seem to dread them as much 
as they do human sponges. I am working nightly for four 
or five hours at them, but seem to make slow progress ; but 
the labour is most delightful to me, and every day brings 
some new fact before my eyes. I have now named and 
ready for drawing above a hundred different forms of 
spicula, and I am working hard to get them ready for a paper 
for the Eoyal Society, if possible, this season. In the spring 
I shall go to Tenby, and have two or three weeks' work at 
the living specimens, and work out all my suspicions and 
beliefs regarding them." 
The result of this visit to Tenby was stated in a paper 
read at a meeting of the British Association in 1856, " On 
the Vital Powers of the Spongiadce" in which Dr Bower- 
banks proved by observations made on Hymeniacidon carun- 
cula, that this sponge possessed the power of expanding and 
contracting the oscula at pleasure while in a living condi- 
tion, but he could not at that time satisfactorily determine 
the nature and powers of the imbibing pores, as these organs 
could only be seen distinctly in operation in very young and 
transparent specimens. These observations were followed 
up by others on the fresh- water sponge, Spongilla fluviatilis ; 
and in another communication at a meeting of the British 
