PLATE 30. 



Direct Colour Photomicrograph. 



Three-colour process. 



TRANSVERSE SECTION HEAD OF NEWLY-BORN MOUSE X 8 



Objective Zeiss Planar. 50mm. 



Condenser ... Watson's Universal Achromatic, back com- 

 bination. 



Illuminant ... Incandescent gas. 

 Aux. Condenser Zeiss Kohler condenser, parallel light. 

 Plates Wratten's "M" Panchromatic. 



Three negatives were taken through Wratten's tricolour filters A 

 (scarlet), B (green), G (blue-violet). 



Exposures A, 3 seconds; B and G, 6 seconds each. 



The positive from which the reproduction was made is a trans- 

 parency composed of three Sanger-Shepherd celluloid films, dyed as 

 described on page 206. 



Preparation stained in bulk with borax carmine, counterstained 

 in aniline blue and picric acid. 



Photo. W. B. R. \Tofollowpage208 



