THE MORPHOLOGICAL CONTINUITY OF 

 SCROPHULARIACEAE AND OROBANCHACEAE 



BY 



IRWIN BOESHORE, B. S., Ph. D. 

 With Plates XII-XVI. 



(Thesis presented to the Faculty of the Graduate School in 



partial fulfilment of the requirements for the degree 



of Doctor of Philosophy.) 



CONTENTS 



Introduction 139 



Review of Previous Literature and Discussion 141 



General Morphology of the Root 147 



Histology of the Root 15° 



Comparative Morphology and Physiology of Stem and Leaf 153 



Comparative Study of the Inflorescence 160 



Comparative Study of the Flower 161 



The Calyx 161 



The Stamens 164 



The Pistil 167 



The Ovary 167 



Hairs of the Pistil 167 



The Nectary 168 



The Seeds 169 



Selection of Hosts I 7° 



Summary I 7 I 



Conclusions *74 



Explanation of Plates *75 



Literature cited 1 76 



139 



