Tue Microscopr. 261 
A FINAL REPORT ON THE CRUSTACEA OF MINNESOTA. By C. L. Her- 
rick, Minneapolis, Minn., 1884. pp. 200. 25 plates. 
THE ORIGIN OF SPECIES. By Charles Darwin. Complete in two 
parts, 30 cents each. p. 260. 
THE CHILDHOOD OF THE WORLD, a simple account of man in early 
times. By Edward Clodd. 
ILLUSIONS, a psychological study. By Jas. Scully. 
The three works mentioned are from the house of J. Fitz- 
gerald, No. 20, Lafayette Place, New York. They are for sale 
by Willis Boughton, Ann Arbor, Mich. 
DruGs AND MEDICINES OF NORTH AMERICA. J. U. and C. G. Lloyd, 
Cincinnati, Ohio. 
The October number of this quarterly contains some beauti- 
ful illustrations and is well filled with reading matter. It is 
receiving a handsome reception from botanists and pharmacists. 
To Mount Bone.—Unsoftened sections of bone may be suc- 
cessfully mounted in Canada balsam or damar solution, and 
exhibit their canaliculi very clearly if they are coated with a 
thin film of strong, clean gum previous to being placed in those 
reagents. A film of collodion may also be used in place of the 
gum.—Cole’s Studies. 
THE Droscopr.—The dioscope does for the eye what the 
telephone does for the ear. An objective lens is fitted in some 
hall of entertainment, and by an electric wire communication 
is established with a small white glass plate in a room, at any 
distance. Excluding the ight from this room, a complete re- 
flection is obtained of what is passing in the hall.—£z. 
THE PINEAL GuAND.—The pineal gland of vertebrates has 
been a stumbling-block in the way of morphologists, and in a 
recent paper Ahlborn supports the view, recently advanced, 
that it is the rudiment of a primitive median eye, adducing in 
evidence the fact that it is connected with the optic thalami; 
its method of formation, and its position in the lower verte- 
brates and in the amphibians. The author thinks it permissible 
to compare it with the single median eye of tunicates and Am- 
phioxus. 
