ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



397 



(3) Cutting, including: Imbedding- and Microtomes. 



New Hand Microtome with Tubular Clamp.* — Dr. Adr. Fiori has, 

 with the aid of Koristka, invented a hand microtome which is intended 

 for sectioning vegetable tissues. The apparatus is of the ordinary shape, 

 i.e. it is cylindrical, is surmounted by a circular cutting-plate, and has 

 a micrometer screw at the lower end for raising the object-carrier 

 (fig. 101). The micrometer screw is marked off in ten divisions, each of 

 which corresponds to a rise of five-hundredths of a mm., while a groove 

 at the lower end of the body serves, due regard being observed as to 

 levelling, as a guide for estimating the distance traversed by the screw. 

 The body of the microtome is cut away to allow the piece C of the 

 object-carrier to be screwed up and down. The opening has a narrow 



Fig. 102. 



prolongation upward for the passage of the screw D. Its edge, when D 

 is not engaged in the prolongation, serves to prevent the clamp from pro- 

 jecting above the level of the cutting-plate. The object-carrier consists 

 of three parts, a hollow tube (fig. 102 A) connected externally with the 

 body and internally choke-bored above to a cone-shape. This tube is 

 screwed below to a second hollow tube (fig. 102 B) terminating above 

 in a tubular clamp. The internal diameter of this clamp is 14 mm., 

 and its upper end is conical. The clamp is split longitudinally in four 

 places, so as to make four jaws, which, when the tube A is screwed up, 

 approximate and diminish the internal diameter of the clamp by 1^ mm. 

 after the manner of a crayon-holder. At the lower end of the second 



Malpighia, xiii. (1899) pp. 193-9 (3figs.). 



