
74 THE NORTHERN MICROSCOPIST, 


ROCHDALE AND WHITWORTH MICROSCOPICAL SOCIETY,— 
At the usual monthly meeting of this Society, J. W. Mellor, Esq., presiding, 
Dr. A. Welsh read a paper on ‘‘ The Borderland of Plants and Animals.” 
At the close of the discussion which followed, some very interesting Microscopic 
organisms were examined, comprising the spawn of the Trout, shewing the 
circulation of the blood. 
The larva of the Ephemera (May Fly) also shewing. the circulation, and Vol- 
vox Globator. 
Mr. T. Spencer Smithson shewed some slides of Arranged F oraminifera, etc, 
Mr. Alderman Hudson shewed a piece of Silk, svfpposed to be the work of 
the gossamer Spider. 
The Secretary shewed longitudinal and transverse sections of the jaw of the 
Mole, with all the teeth zz sz¢u. 
The Society, which is in a fairly healthy condition, has a good syllabus of 
papers promised for the coming session. 
The ordinary monthly meeting of the Society was held on Thursday evening, 
the 2nd of February, Henry Standring, Esq., in the chair. 
After the usual preliminary business of the Society had been transacted, a 
paper was read by the Hon. Sec., Mr. I. Renshaw, L.D.S., subject, ‘‘ The 
History of a Human Tooth,” illustrated by diagrams and Micro-slides, repre- 
senting its development, character of structure, and causes of destruction. 


NOTES AND QUERIES. 
CATALOGUE OF THE DIATOMACE®.—We have received a notice 
that Part I. of this catalogue is now complete; it is a complete 
index to the literature describing or figuring the Diatomacez, 
published previous to the year 1881. The species are alpha- 
betically arranged under the genera, with references to the 
descriptions in chronological order. It embraces a list of more 
than five thousand species. 
OpiTuARY.—The death is announced of Professor Theodore 
Schwann, of Liége, at the age of seventy-two. He may be said to | 
occupy in biology the same position that Faraday holds in the 
history of electricity. In 1839 Schwann published his “cell 
theory,” which asserts that the most different elementary parts of 
organisms are developed on one common principle, and that this 
principle is cell-formation. This theory, and the investigations by 
which it was supported, had an important effect on the study of 
biology—in fact, it marks an epoch in the history of that science. 
IMPROVEMENTS IN TURNTABLES.—An improvement in Kinné’s 
selfcentering turntable has been lately devised by Mr. W. D. 
Smith. In theory this table is perfect, but unfortunately glass 
slips are seldom if ever cut quite accurately, so that the slip instead 
of being exactly in the centre is a little to one side of it. The 
improvement referred to consists in substituting for the angle pieces 
en 

