GENEEAL MORPHOLOGY OP THE PLANT 



division of the vegetable kingdom which bears the name 

 Thallophyta in consequence. 



Prom the Thallophyta by various intermediate stages, 

 through an order of plants called Liverviforts, we arrive at 

 another group — the Mosses. In the lower forms of the Liver- 

 worts, e.g. Marchantia (fig. 7), we have a green flat thallus-like 

 stem bearing upon its under-surface scale-hke appendages, which 

 some botanists have considered to be the first representatives 



KiG. i. 



Fig. 5. 



^z</. 4. Another mould (-SwTO/z»m) Fit/. 5. Thallus or thallome of 



with reproductire cells ar- tlie common Bladder Seaweed 



ranged in rows on a special (Fucwt vesicujosus), /, /. The 



branch. fructification, v, v. Bladders 



containing air. 



of true leaves. In the higher forms, as Jungermamnia {fig. 8), 

 the stem and leaves are both more highly developed. 



With the exception of some of the higher Mosses, such as 

 Polytriohum, all the plants so far described are composed mainly 

 of cells which approach more or less closely to the spherical or 

 oval form, or which, if elongated, are thin-walled and commonly 

 flexible, and they are hence often termed Oellidar Plants, in 

 contradistiuiction to those above them in order of development, 

 which are called Vascular Plants. These are so named on 



