

CONTENTS. 



Page 



Introduction 1 



I. Methods 3 



II. Experimental Part 3 



Juncus effusus 4 



Allium cepa 4 



Equisetum limosum 6 



Ricinus communis (petiole; 7 



Triticum repens ... 8 



Zea mais ... 9 



Caltha palustris 10 



Lamium garganicum 11 



Cucurbita pepo 12 



Althaea tauriensis 14 



Urtica dioica 16 



Dahlia variabilis 17 



Archangelica sativa 20 



Myrrhis odorata 23 



Vicia faba 24 



Melianthus major 29 



Ricinus communis 32 



HI. Discussion 36 



1. Effect of gypsum casts on the functional activity of meristematic tissue 36 



2. Effect of gypsum casts on the growth of thin-walled parenchyma. . . 38 



3. The formation of cavity by the destruction of cells and its prevention 



by the use of gypsum casts 42 



4. Effect of gypsum casts on the growth of supporting and conducting 

 tissue 45 



5. Changes outside the casts 48 



IV. Results 49 



Vita 50 



