910 
PROCEEDINGS OF THE SOCIETY. 
Mr. Bennett said there could be no doubt that all who were 
acquainted with alg© or diatoms would regard this paper as one of 
extreme interest. He should like to refer to one or two points which 
had occurred to him in connection with the subject, and especially to 
mention that in the allied family of desmids he had observed structures 
which he thought might be of similar character, and he had noticed that 
they quite agreed in the habit of attacking one or two species only, so 
that in a gathering containing many species one might be found infested 
and the others quite free. He should like to inquire if by the term 
spores Mr. Gill did not mean zoospores ? Had he observed them to be 
possessed of vibratile cilia ? Or could he form any idea as to how they 
came to be inside the diatoms ? He could hardly think they would be 
able to penetrate the fully formed siliceous shells, though they might 
get through during earlier stages of growth when the envelope was less 
completely hardened. It was perhaps possible that they might be trans- 
mitted in some way by inheritance, and if so that might account for 
their great abundance in a particular speoies, but not in others in the 
same gathering. There were so many interesting points which cropped 
up in connection with this subject that he wanted to be able to see it 
in print in order to take them into consideration. 
Prof. Bell hoped that if Mr. Gill had assured himself that Zopf’s 
paper was not in their library, as he imagined, he would let Mr. Brown 
have its full title in order that a copy might be obtained. 
Mr. Karop said that the paper originally appeared in the 4 Nova 
Acta,’ and therefore it was certain they must have it. 
Mr. Bennett said the paper had come under his notice in some way, 
and his impression was that it had been noticed in the Journal. 
Mr. Gill said that the question as to how these things originally got 
into the diatoms was one still under consideration ; he had therefore 
particularly avoided saying anything definite upon the subject because 
he had not yet worked it out. As to the movements of the spores, he 
was not at present perfectly certain that they moved at all more than 
a very short distance from the orifice of the beak, but he had not yet 
had time to examine them sufficiently to be able to answer the question 
as to whether they were oiliated. 
Mr. Karop thought Zopf said that they got into the diatoms. 
Mr. Gill said this was quite possible, because diatoms were by no 
means the tightly shut up boxes which they were supposed to be. They 
could not live or absorb nutriment unless there was some sort of passage, 
and he thought there was very likely a means of penetration all over 
them to admit of the diffusion of fluid throughout. 
Dr, P. M. Braidwood thought that a very important point was 
involved in this question of cultivation, which if decided, might yield 
great results. They were dealing with very minute organisms, and the 
suggestion made appeared to him to be a very pregnant one indeed, so 
that he hoped some one would give it the attention which it seemed to 
deserve. 
The President was sure that all who were interested in the subject 
would agree that this was probably only the beginning of what might 
be a very important series of observations. 
