1892.] THE MICROSCOPE. 137 



in good alcohol to make it take stain more readily. Stain in 

 carmine or hfematoxylin. snip oft\a small piece and separate the 

 elements in glycerine, with needles, thus making teased prepara- 

 tions. 



34. W/iat is the disease Botj-yo-iuycosis^ iv/iere is it found 

 and ivhei'e can notes or literatnre be found ? 



Botrvo-mvcosis is a fungoid disease found in horses. It pro- 

 duces masses of small nodules in the lungs, resembling bunches 

 of grapes ; the name xwq-aw^^ grape-like fungus. 



35. Is there anything known about the 7iervous system in 

 fresh-ivater sponges., and is there any literature? 



See A7n. Mo. Mic. journal., vol. VI, pge. 156 ; also vol. 

 VII, pge. 205. 



36. Can y 071 give 77ie clear directio7is for 7isi7ig the Abbc- 

 Zeiss Ca77iera Lucida? 



This camera lucida consists of a prepared cube of glass 

 mounted in a setting arranged to slip over the eye-piece of the 

 microscope, and an attached arm supporting a plane mirror; the 

 glass cube contains an internal silvered reflector with a small 

 central visual aperture. The microscope tube should be vertical 

 and the drawing paper at the right, in a plane parallel to that of 

 the object. Place the cube over the eye-piece, centre it so its 

 visual aperture will be in the optical axis, the reflecting surface 

 upward and toward the right, at an angle of 45°. The attached 

 mirror must be directly above the drawing paper, its surface at an 

 angle of 45°, to reflect the image of the paper to the silvered sur- 

 face in the glass cube. The eye in position sees the object 

 through the clear central portion of the cube, also the image of 

 the pencil and paper on the silvered surface surrounding this 

 aperture, blending into one picture apparently on the drawing- 

 paper. The illumination of the object, and also the paper, must 

 be reofulated to secure g-ood definition. This camera was in- 

 tended for use with a vertical microscope, but the tube may be 

 inclined provided the drawing board is placed at right angles to 

 its axis. 



37. Where ca7i I fi7id directio7i for usi7ig the Tho?7ia-Jung 

 7nicroto77ie for parafi7ie sectio7i^ a7id can it be used for cel- 

 lo i din? 



See answer to Qiiery No, 35. 



The Thoma-Jung. Schanze, B. & L., and all such microtomes 

 are practically similar in their operation, diflering only in the 

 mechanical details for raising the object to the knife. Parafiine 

 or celloidin imbedded material can be equally well cut, and no 

 special method is necessary for either instrument. 



