PLANT MICRORADIOGRAPHY 



EXPLANATION OF PLATES (white areas on figures correspond to the most highly absorbing mat- 

 ter, black to little or no absorption). 



Be winiJ»rv 



cellophane, spttimfti, film 

 Sfrillg 



*3 re 



" cani(ra moving 



graduate rule 



'■ ■'■■■■ t I I 



in m>^<lllc tube 



PI. I — Fig. 1: Contact microradiography (CMR) equipment used for plant materials (1 to 20 kV). 

 Technique is described in te.xt as "Histological technique of MR". 



Fig. 2: Reference papers impregnated with heavy ion salts of increasing concentration and 

 macroradiographed, XI 



Fig. 3: Photographic film reference system (Kodak) for comparison of intensities of a micro- 

 radiograph 



Fig. 4: Arrangement of specimen to be radiographed and film inside camera moving in cylinder 

 fixed to the x-ray tube 



Fig. 5: Cigarette paper impregnated with heavy ion salt and microradiographed b}' contact be- 

 fore desiccation, X50 



Fig. 6: The same paper microradiographed after evaporation. Notice that crystallization is ori- 

 ented by direction of fibers, X50 



Fig. 7: Another reference salt system composed by diverse concentrations of solutions put in 

 small cylinders hollowed in Perspex block, XI 



639 



