1893.] THE MICROSCOPE. 87 



cross-piece above the batteries and below the table surface. It 

 is provided with two pulleys from which belts pass to the 

 shaft on the table, which carry the grinding disks and diamond 

 saw. The grinding apparatus consists of two circular disks of 

 solid copper 9 inches in diameter and three-eighths of an inch 

 thick, which may be used alternately as different grades of em- 

 ery are required. They are attached either by a screw or 

 square socket to a vertical iron spindle which revolves 

 smoothly in a conical bearing. The grinding disk is sur- 

 rounded when in use by a large cylindrical pan of tin which 

 has an opening in its centre to allow of the passage of the 

 spindle. 4. The sawing apparatus consists of a horizontal 

 counter-shaft placed on a different part of the table from the 

 grinding disk and connected with the moter by a separate belt. 

 It carries at one end a vertical wheel of solid emery and at the 

 other an attachment, level-table and guide for the diamond 

 saw. A small water can and spout are suspended over the 

 level-table to keep the edge of the saw wet when it is in use. 

 Under some circumstances it may be found advantageous to 

 obtain electricity for this motor by a direct wire from an elec- 

 tric light or power company. Considerable inquiry has shown, 

 however, that in Baltimore the storage batteries are more con- 

 venient, safe and economical ; a single charge lasts for the 

 needs of a laboratory of ten students for a month. The bat- 

 teries are removed by the electric company, and returned with 

 little or no delay, at a cost of S3. 75 for recharging. — American 

 Journal of Science. 



■ooo- 



SECTION OF RUTABAGA TURNIP. 



[From Note- Book P, of the American Postal Microscopical Club] 



BY R. II. WARD, M. D., TROY, N. Y. 



This is a mass of nearly simple cellular tissue, though formed 

 from the layers which usually produce wood, naving no func- 

 tion but to be gorged with food-prodncts for the future use of 

 the plant or of its cultivator. Some of the stained nuclei 

 show in front view as roundish discs, and others, in edge view, 

 as lenticular thickenings of the vertical cell-walls. The ab- 

 sence of starch from the cells of this parenchyma is a notable 

 contrast to its abundance in most tubers, root-stocks, etc., while 



