ZOOLOGY AND BOTANY. MICROSCOPY. KTC. 



389 



of serial sections as they are automatically carried along, unfolded, and 

 delivered without hanging down from the back of the knife. A band- 

 gear (fig. Ill) is secured to the knife and consists of an endless band 

 running on two rollers, which are set crosswise through the two ends of 

 a tube. In order that the band may always be kept taut, the tube is 



Fig. 111. 



formed of two pieces fitting into one another and pressed outwards by [a, 

 spiral spring lying in the interior of the tube, the tube being carried by 

 a clamp fastened by two pressure screws on the knife-back. These 



Fig. 112. 



screws are set behind one another, not sidewise, so that it is possible to 

 arrange the band horizontally or oblique. The roller is thus close 

 behind the knife-back. In the axis of the other roller there is a toothed- 

 wheel. An angle-piece carrying a clutch is fastened on to the arm 

 which bears the chain-wheel. This clutch projects from the end of a 

 staff which is adjustable in its length, and at its place of attachment is 



