xviii INTRODUCTION 



THALLOPHYTA. Lower Plants. 



Plants without stems, leaves and vascular tissue. 

 Either unicellular or consisting of a mass of cells 

 called a "thallus" 

 CORMOPHYTA. Higher Plants. 



Plants (exeept in the lowest forms) with leaves, 

 stems and vascular tissue. All with an elaborate 

 mode of sexual reproduetion. 



We wish, however, to emphasise the fact, that the 

 thallophytes as well as the eormophytes comprise groups 

 of plants which do not exhibit any speeial signs of mutual 

 relationship, and that the arrangement is mainly one of 

 convenience. 



THALLOPHYTA. (Div. I to XL) 



CORMOPHYTA. (Div. XII to XV.) 



A. Archegoniatae. 



Division XII. BRYOPHYTA. 



Class I. HEPATICAE. Liverworts. 

 Class II. MUSCI. Mosses. 



Division XIII. PTERIDOPHYTA. 

 Class I. FILICINAE. 



A. Filices. Ferns. 



B. Hvdropterides. Water-Ferns. 



Class II. EQUISETINAE. Horse-tails. 

 Class III. LYCOPODIINAE. Clubmosses. 



B. Anthophyta. Flowering Plants. 

 Division XIV. GYMNOSPERMAE. 

 Division XV. ANGIOSPERMAE. 



Class I. DICOTYLEDONES. 

 Class II. MONOCOl YLKDONES. 



