Plate XII. Figure A, aldehyde in a single liver cell. The large, clear 

 spherical body is the nucleus, and the two dark rings are zones of high 

 aldehyde content surrounding two fat droplets. There is also diffuse alde- 

 hyde in the cytoplasm. The surrounding cells are devoid of aldehyde. 

 Figure B, carbohydrate in rat intestinal mucosa, revealed by periodate 

 oxidation. Note high concentrations in the absorbing borders and in the 

 goblet cells, and a much lower concentration in the Golgi zone of the 



absorbing cells. 



