86 THE FROG 



Anglers' Bait and Mfg. Co., 333-335 West South Water St., Chicago. 

 (Live and preserved frogs.) 



Bausch and Lomb Optical Co., Rochester, N. Y. (Microscopes and 

 accessories; dissecting instruments.) 



Bect'en, Dickinson and Co., Rutherford, N. J. (Liier syringe, for 

 injecting arteries.) 



Biological Supply Co., 106 Edgerton St., Rochester, N. Y. (Live and 

 preserved frogs.) 



Brimley Bros., Raleigh, N. C. (Preserved frogs.) 



E. R. Neuenfeldt, 225 North Clark St., Chicago, 111. (Live frogs.) 

 Ernst Leitz, 30 East i8th St., New York. (Microscopes and acces- 

 sories.) 



F. D. Lambert, Tufts College, Mass. (Live and preserved frogs; 

 arteries injected.) 



Kny-Scheerer Co., 225 Fourth Ave., N. Y. (Preserved frogs; ana- 

 tomical preparations and models; syringe for injecting arteries; dis- 

 secting instruments; charts.) 



Marine Biological Laboratory, Supply Department, Woods Hole, 

 Mass. (Preserved frogs; arteries injected.) 



Southern Biological Supply Co., Natural History Building (opposite 

 Jackson Square), New Orleans, La. (Live bullfrogs.) 



Spencer Lens Co., Buffalo, N. Y. (Microscopes and accessories; 

 dissecting instruments.) 



Ward's Natural Science Establishment, Rochester, N. Y. (Pre- 

 served frogs; anatomical preparations and models.) 



III. CARE OF LIVING MATERIAL. 



Live frogs may be kept in a tank containing one or two 

 inches of water. Frogs in captivity often die from the at- 

 tacks of parasites; loss from this source may be minimized 

 by frequently cleaning the tank and changing the water, 

 also by keeping only a small number of frogs in a single 

 tank. If kept in a cool place, frogs do not require food 

 during the winter season. 



In the laboratory a few frogs may be kept for observation 

 and experiment in small cages supplied with water. Insect 

 cages are excellent for this purpose ; they should open at the 

 top. For studying the swimming and diving movements a 



