314 



Mr, A. D. Michael described a typical specimen of Platyr/ aster, which he 

 had brought for exhibition, and which he also figured on the black board. 



Mr. J. G. Waller read a short paper in reply to observations made at the 

 preceding meeting in opposition to his paper on the so-called boring sponges. 

 (See page 265). 



The President said he was afraid the subject was one on which there was 

 likely to be disagreement of opinion for a long time to come, so that he 

 thought it would not be wise to open the discussion again ; they would, 

 however, be glad to hear anything which Mr. Stewart might like to say on 

 the observations just made. 



Mr. Chas. Stewart said that the remarks which he made at the last meet- 

 ing were, in the first place, chiefly dix'ected against a kind of false logic 

 which it seemed to him was being employed, and it was for this reason that 

 he referred to the action of the atmosphere on glass. Mr. Waller said that 

 a soft body like the sponge was incapable of removing a hard substance 

 like shell or rock, but this appeared now to be admitted as a possibility. 

 Mr. Waller also said that the character of the surface of the cavity was such 

 as alone could be made by the gnawing of some annelid, and therefore it 

 must be done in that way. He, however, maintained that this was not a 

 necessary conclusion, because the pieces of glass, which were veiy much 

 harder than shell, showed the same or very similar effects of erosion ; it was 

 merely to show that the character of the cavity was not in itself conclusive. 

 Mr. Waller seemed to feel great diflBculty in recognising the similarity 

 between the process going on in a living animal — in the removal and deposit 

 of bone for instance — and that which might be going on in the case of some 

 sponges ; but it was clear that the living mantle of a mollusk could both 

 deposit and destroy the same substance ; and in the case of bone they could 

 not regard the whole substance, though part of a living animal, as being 

 itself alive — the lime, &c., was as practically dead as the shell — so that if 

 they found a similar character of erosion produced in other hard substances 

 by the action of soft ones, it was not improbable that they might find it in 

 the case of Cliona. Two theories were put forward, one being that the 

 borings were made by an annelid, and the other that they were made by a 

 sponge, and he could only say that, looking at the matter on all sides, the 

 greater probability seemed to be that the soft substance of the sponge 

 made the borings. 



Mr Waller said his contention was that the action of a soft substance 

 could not produce sharp edges. 



Votes of thanks to Mr. Groves, Mr. Michael, and Mr. Waller for their 

 communications were unanimously passed. 



Dr. Matthews having taken the chair. 



The President read a paper " On the Histology of the Gustatory Organs 

 of the Rabbit's Tongue," the subject being illustrated by coloured diagrams 

 and specimens exhibited under the microscope in the room. 



Dr. Matthews said he had listened with intense interest to this paper, 

 and should be glad to hear the remarks of some of those present in further 

 elucidation of the subject. He should like very much to know if in the 



