74 THE MICROSCOPE. _ May 
QUESTIONS ANSWERED. 
Notg.—Dr. S. G. Shanks, of Albany, N Y., kindly consents to receive al, sorts of ques- 
tions relating to microscopy, whether asked by professionals or amateurs. Persons of ats 
Ee ades of experience, from the beginner upward, are welcome tothe benefits of this depar* 
ment. The questions are numbered for future reference. 
a ae 
Q. 250.—T would like to know how to preserve and mount Daph- 
nia and similar crustaceans. In several places the Journal says: 
“take strong carbolic acid.’’ TI have tried every strength from that 
down to 2 per cent. and always find that the shells expanded like 
wings and antennae drawn down to sides ?—W. S. O. 
Collect the Daphniz ina very small quantity of water in 
a watch glass; then hold it over a lamp-flame so as to 
heat it quickly. The Daphniz will die almost instantly, 
and may then be placed in the G. W. A. mixture (Glycer- 
ine 1, Water 2, Alcohol 3) in a watch glass, or the like, 
loosely covered, to protect it from dust. Allow the alcohol 
to evaporate and slowly concentrate the mixture. Mount 
in dilute glycerine or in Farrant’s medium. 
Q. 251.—Was Gundlach American or German? Are there two 
Gundlachs or only one ? 
A.—The only Ernst Gundlach was born in Germany. 
—~+ 
PRACTICAL SUGGESTIONS. 
By L. A. WILLSON, 
CLEVELAND, OHIO. 
Pediastrum.—For exhibition at a microscopical soiree, 
few things are more interesting thana pediastrum. They 
generally can be found in most collections of water especi- 
ally the filtering of the water supply of the great lakes. 
Diligent search may often discover myriads of them in 
ponds. They are described in Carpenter’s Seventh Edi- 
tion at page 498. 
To exhibit a pediastrum, place one on a slide covered 
with water, move the slide to exhibit the object in the cen- 
ter. It will be best to display the specimen with a one 
