GENERAL METHODS. 2$ 



convenient a little apparatus to which Ranvier has given (I, 

 66) the name photophore (light-bearer), but which may better 

 be called, with Obersteiner (I, 55), section-finder. It consists 

 of a wooden box, about 5 cm. high and 10 to 12 cm. long 

 and wide, whose front side is wanting, while the top is 

 replaced by a plate of clear glass. There is placed in this 

 box a small mirror so inclined toward the front that it forms 

 an angle of 25 to 30 with the bottom. If this mirror is 

 now turned toward a brightly-lighted window, it will, plainly, 

 reflect the light against the plate of glass forming the top of 

 the box and against the dish of staining fluid placed upon 

 it. One can easily prepare such an apparatus. 



The apparatus described by Eternod (I, 41), shown in Fig. 



FIG. 12. Eternod's apparatus. 



12, is also very convenient. In this the front part of the 

 glass plate c, which is lighted by the mirror #, serves as a 

 section-finder, while beneath the hinder part of the glass 

 plate d-d is a strip of paper divided into variously colored 

 portions. The outlines, prepared with a diamond, at g 

 serve, as is plain without further explanation, for the center- 

 ing of preparations on the slide, and the small turn-table a, 

 for preparing cement rings, etc. 



37. Microtome sections which are to be stained after cut- 

 ting are usually fastened to the slide (see 50-52). If 

 it is desired to place a large number of sections in the 

 same staining fluid at the same time, this may be readily 

 accomplished with the aid of a number of crystallizing 

 dishes placed inside of each other, as shown in Fig. 13. 

 The space between two dishes is then filled with the stain- 



