290 CHAPTER XXV. 



described by SCHAFFER (Zeit. iciss. Mil-., vii, 1890, p. 342). 

 Careful outlines of the sections to be reconstructed are drawn 

 on tracing paper with the aid of the camera lucida, super- 

 posed, and held up against the light for examination by 

 transparence. VOSMAER (Anat. Anz., xvi, 1899, p. 269) draws 

 on plates of celluloid, and sets them up in a rack for ex- 

 amination. KEKR (Quart. Journ. Mic. Sci., xlv, 1902, p. 1) 

 draws on plates of ground glass which he afterwards super- 

 poses and makes transparent by oil of cloves run in between 

 them. PENSA (Zeit. wiss. Mikr., xxvii, 1910, p. 48) takes 

 sheets of lithographic gelatin. WOOD WORTH (Zeit. wiss. Mil-., 

 xiv, 1897, p. 15) proceeds as follows : (1) Draw an axial 

 line of the length of the object multiplied by the magnifi- 

 cation employed. (2) Measure with a micrometer the 

 greatest diameter of each section. (3) Plot these diameters 

 down transversely on the axial line at distances correspond- 

 ing to the thickness of the sections multiplied by the 

 magnification. (4) Join the extremities of these diameters ; 

 this will give you an outline of the object. (5) Measure off 

 on each section the nearest and farthest limits (from the 

 margin) of the organs to be filled in, and plot them down on 

 the transverse lines (3), and join the points as before, i. t>. 

 from section to section ; this will give you the outlines of 

 the organs. 



This process is best applicable to reconstruction from 

 transverse sections, but it can be applied to reconstruction 

 from sections in any plane if the object can be provided with 

 a plane of definition at right angles to the plane of section. 

 This may be established by cutting off one end of the object, 

 or the like (see also Orientation, 142, 161). 



To make a simple plastic reconstruction, camera drawings 

 (or photographs) of the sections (all made at the same 

 magnification) are pasted on pieces of cardboard of a thick- 

 ness equal to that of the sections multiplied by the magnifi- 

 cation employed. Then the parts of the drawings representing 

 the cavities of the objects are cut out with a knife or fret- 

 saw, cutting through the cardboard ; and the pieces of fret- 

 work thus obtained are pasted together. 



For more elaborate processes of plastic reconstruction (very compli- 

 cated and seldom necessary) see BORN, " Die Plattenmodellirmethode," 

 in Arch. mile. Anat., 1883, p. 591, and Zeit. wiss. Mile., v, 1888, p. 433 ; 



