154 DRAWING WITH THE MICROSCOPE \_CH. V 



If one has many large objects to draw at a low magnification, 

 then some form of embryograph is very convenient. (Jour. Roy. 

 Micr., Soc, 1899, p. 223.) The writer has made use of a photo- 

 graphic camera and different photographic objectives for the purpose. 

 The object is illuminated as if for a photograph and in place of the 

 ground glass a plain glass is used and on this some tracing paper is 

 stretched. Nothing is then easier than to trace the outlines of the 

 object. See also Ch. VIII. 



§ 209. Drawing with the Projection Microscope. — Except 

 for the highest powers and for details of cell structure the projec- 

 tion microscope furnishes the most satisfactory means of making 

 drawings. With it one can draw large diagrams or small figures 

 directly from the objects; and if the apparatus is properly constructed 

 one may make diagrams from objects 60 to 70 mm. in diameter 

 down to those of half a millimeter or less. This method was much 

 in vogue and highly commended by the older microscopiste who 

 used the solar microscope (Baker, Adams and Goring). Since the 

 general introduction of electric lighting drawing with the projection 

 microscope has become once more common and is the most satisfac- 

 tory method known especially for the numerous drawings necessary 

 for the preparation of models in wax or blotting paper. See Ch. X. 



REFERENCES FOR CHAPTER V 



Beale, 31, 355 ; Behrens, Kossel and Schiefferdecker, 77 ; Carpenter- 

 Dallinger, 278 ; VanHeurck, 91 ; American Naturalist, 1886, p. 1071, 1887, pp, 

 1040-1043 ; Amer. Monthly Micr. Jour., 1888, p. 103; 1890, p. 94; Jour. Roy. 

 Micr. Soc, 1881, p. 819, 1882, p. 402, 1883, pp. 283, 560, 1884, p. 115, 1886, p. 

 516, 1888, pp. 113, 809, 798; Zeit. wiss. Mikroskopie, 1884, pp. 1-21, 18S9, p. 

 ' 367, 1893, pp. 289-295. Here is described an excellent apparatus made by 

 Winkel. Greenman Anat. Record No. 7, 1907, pp. 170-178. Gage, Origin and 

 Development of the Projection Microscope. Transactions of the Amer. Micr. 

 Soc, Vol. XXVIII, 1906. Consult also the latest catalogs of the opticians. 



