OL} 
PROCEEDINGS OF SOCIETIES. 
Royat MicroscopicaL Society. 
Kine’s CoLttecr, December 6, 1876. 
H. C. Sorby, Esq., F.R.S., President, in the chair. 
The minutes of the preceding meeting were read and confirmed. 
A list of donations to the Society was read by the Secretary, and 
the thanks of the meeting were voted to the donors. 
The President exhibited a facsimile of the first compound micro- 
scope ever constructed, made in 1590 by Zacharias Janssen, which he 
had been allowed to copy from the original in the possession of the 
Scientific Society of Zeeland, at Middleburgh, in Holland. 
A paper by the Rev. W. H. Dallinger, “On Nawicula crassinervis, 
Frustulia Saxonica, and Navicula rhomboides,” was read by the Secre- 
tary, and a series of very beautifully executed drawings in illustration 
was exhibited. The paper appears at p. 1. 
The President, in proposing a vote of thanks to Mr. Dallinger for 
his communication, considered it very interesting in more ways than 
one, and that the manner in which the investigations had been carried 
out was most excellent. The remark made towards the end of the 
paper was worth remembering—that to say a lens would resolve a 
certain kind of diatom was a statement of little value, seeing that the 
varieties of the same kind were so very different in size and re- 
solvability. He judged, however, from the paper that there was no 
difference between the fineness of the markings of frustules of the 
same species, provided that they were of the same size; so that if the 
size of the specimen resolved by any lens were stated, a much more 
definite opinion could be formed of its quality. With regard to some 
of the statements made by Dr. Woodward, he would mention that he 
wrote to him some time ago, and suggested whether there might not 
be some difference observed in the number of the markings when 
light of different kinds was used. Dr. Woodward had told him he 
had tried some experiments in the matter, and believed there were 
some such differences, but it would take much time to follow the 
matter up thoroughly. He hoped that at some future time they 
should hear further upon the subject. He thought, if they might 
judge from the tone of what had taken place lately, there seemed to 
be just now a great tendency to reverse the process adopted by 
naturalists some time ago, of adding as much as possible to the 
number of species into which a genus could be divided, by now 
uniting all the extreme varieties. 
A vote of thanks to the Rev. W. H. Dallinger was unanimously 
carried. 
Mr. H. J. Slack thought these drawings of Dr. Dallinger’s were 
very interesting in an optical point of view. Microscopists were 
often told by others that they spent their time in counting dots and 
scratches; but unless, as in this case, they did give some careful atten- 
tion to these dots, they would be likely to miss facts of the greatest 
