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Tue Microscopes. 111 
lutely unknown, though there is every reason to believe that it 
was introduced with a pond-weed. Its structure was such as to 
lead one to believe that it had a hydroid condition, and last year 
Mr. A. G. Bourne found in the tank a number of hydroids, 
which, there is every reason to believe, is the other stage of the 
species. Itis very small and is even more simple than Hydra, 
for it has no tentacles. Figures of this Hydroid and details of 
the dates of its appearance may be found ir. the Proce. Roy. Soe., 
XXXvili, 1885. 
EDITORIAL NOTES. 
THe New Ossectives.—All our readers will be greatly in- 
terested to hear more about the ‘‘ New Objectives” mentioned 
in an editorial in our last issue. We, therefore give them the 
benefit of an article in the April number of the Journal of the 
Royal Microscopical Society. 
Mr. Gunpiacu’s OpsectivEes.—We. have had in our posses- 
‘sion, for some time, one of Mr. Gundlach’s one-tenth water im- 
mersion objectives of 105° angular aperture (water), with a 
working distance of about 1-50 inch. The glass is listed at $26, 
and is composed of three systems. Taking the above facts into 
consideration it is one of the best glasses of its kind we have 
ever seen and would call particular attention to it as a very de- 
sirable working lens. 
Mr. WALMsLey’s: Vistr.—We have been enjoying a short 
visit from Mr. W. H. Walmsley, of Philadelphia. Mr. Walms- 
ley always brings good cheer and a store of new ideas. We 
were simply charmed with the beautiful products of his work in 
photo-micrography and general photography. Taking together 
his own skill, the Beck lenses, and the bromide paper, and we 
have apparently the three essential things to make Amateur 
Photography a complete success. We shall invest in two of 
these essentials and shall get as much of the third as Mr. Walms- 
ley can impart tous. He says he is selling hundreds of their 
new “Star” microscopes and all purchasers declare it “ the best 
cheap microscope in the market.” We clip the following from 
the Photographic Beacon concerning his work in Photo-microg- 
