MAR 6 1800 
X' 
JOURNAL 
OF THE 
ROYAL MICROSCOPICAL SOCIETY. 
FEBRUARY 1899. 
TRANSACTIONS OF THE SOCIETY. 
I. — The Reproduction of Biatoms. By J. Newton Coomde. 
( Read 19 th Octal er, 1898.) 
Plates I. and II. 
In a paper read by Mr. George Murray, F.R.S.L. and E., F.L.S., 
before the Royal Society of Edinburgh, and published in the Society’s 
Proceedings, vol. xxi. No. 33, the question as to whether diatoms 
are reproduced by spores or endocysts, in addition to their other 
known modes of reproduction, is brought from the region of specula- 
tion, in which it had been buffeted about for nearly fifty years, to that 
of actual observation. 
In an article which I contributed to ‘ Le Diatomiste ’ (No. 21, 
June 1895), after suggesting that Dr. Miquel’s failure, in his in- 
teresting laboratory cultivations, to discover any appearance of spores 
among the Diatomaceae, may have been due to the fact that his in- 
vestigations were made among artificial growths which it is possible 
were deficient in some of the elements necessary for the development, 
or even fertilisation, of diatom spores, if any such existed, I mentioned 
the case of a natural gathering of Navicula radiosa Kiitz., in which 
I found “ corpuscular bodies similar in colour, size, and shape to those 
seen in the interior of the largest frustules in the gathering, mixed 
with frustules of every size, varying from about 5 /x, the size of the 
corpuscles, to about 95 /x, the size of the largest frustule.” In one 
of the illustrations which accompanied my article, and which I drew 
with the aid of the camera lucida, there is shown a frustule containing 
two round bodies apparently in the act of escaping from a full-sized 
frustule of the species indicated. 
When my attention was directed to Mr. Murray’s paper, I wrote 
to Professor Herdman, of the University College, Liverpool, and he 
very kindly made arrangements for my being supplied from the 
Note. — The explanation of plates I., II. is given in the text. The magnification 
is cir. 144 for figs. 1, 2, 3, 5, 10, 11, 12, 13, 14, 15, 19, 20 ; cir. 260 for figs. 4, 6, 7, 8, 
9, 16, 17, 18. j 
1899 
3 
B 
