1895 THE MICROSCOPE. 45 



Paramecia or other infusoria upon a slide, drop a minute 

 quantity of tannic acid. If the solution is too weak, the cilia 

 are not immediately arrested, but if the solution U of the proper 

 strength they will stand out straight. After this treatment 

 the infusoria appear beautifully with a paraboloid. The solu- 

 tion of tannin is made by dissolving one part of tannin acid in 

 four parts of glycerine. 



Collecting Specimens. — During March, April and May 

 many beautiful specimens may be collected from ponds. 

 Scrape off any gf^latinous matter. For small animals use a 

 small hand net, made of common cloth and troll this along 

 the bottom. Such a net must not be more than three inches 

 in diameter. 



SCIENCE-GOSSIP. 



Lisf of Exhibits at the Eighth Afmiial Exhibitio?i, Department of 

 3Ticroscopy of the Brookly?i Institute of Arts and Sciences, Art Associ- 

 ation Hall. IJ4 Montague St. , Brooklyn, Moftday, fanuary 14, i8g5. 



Bausch & Lomb.— Micro-Photographs. Descent from the Cross, 

 aud Portrait of Dr. Carpenter, F. R. M. S. Arranged diatoms. Head 

 of louse, Pediculus capitis. Sea sand, Bermudas. Trachaea-potato bug, 

 Doryphora decemlineata. 



W. Bowdoin. — Vinegar eels. 



Mrs. W. G. Bowdoin. — British diamond beetle, Phyl. ponioua. 



Frederick Kato. — Zmc oxide, an accidental crystallization. 



Prof. W. C. Peckham. — lyingual ribbon of poludina. 



C. P. Abbey. — Bouquet of butterfly scales, composed of 135 pieces. 



Geo. W. MuUer. — Polycystina. 



Horace W. Calef — Hairs of sea mouse, Aphrodite aculeata. These 

 hairs form tufts of bristles which encircle this marine, spindle-shaped 

 worm, and serve as weapons of defence. 



Henry F. Crosby. — Foraminifera, Gulf of Mexico. 



A. H. Bhrman. — Elytron (wing case) of diamond beetle, Entimus 

 regulis. Pollen of corn cockle, showing anther beards, polarized. 



James Walker. — Six rock sections from the drift of Brooklyn, shown 

 with automatic revolving stage and polarized light. Cacoxenite on 

 limonite, from Lancaster Co,, Pa., a hydrous basic phosphate of iron. 



Louis W. Froelick — Spines of echinus. 



M. H. Wilckens. — Sections of cork. 

 . Dr. Heber N. Hoople. — Ovary of canna, cross section. 



Frank Healy. — Crystals of salicin, shown with polarized light. 



Dr. J. W. Metcalf. — Citric acid, shown with polarized light. 



