344 MICROSCOPIC STRUCTURE OF HIGHER CRYPTOGAMIA. 



structure, and perforins the same actions as every other part, living 

 for and by itself alone. In Batraclwspermum, (Fig. 157) we have 

 seen a definite arrangement of branches upon an axis of growth ; 

 and while the branches are formed of simple necklace-like rows of 

 rounded cells, the cells of the stem are elongated and adhere to 

 one another by flattened ends. This kind of differentiation is seen 

 to be carried to a still greater extent in Mesogloia (Fig. 160), a 

 plant that may be considered as one of the connecting links be- 

 tween such Protophytes as Batrachospermese, which it resembles 

 in general plan of structure, and the Fucoid Algse, which it re- 

 sembles in fructification. 



257. "When we pass to the higher Sea-weeds, such as the com- 

 mon Fucus and Laminaria, we observe a certain foreshadowing 



Fig. 161. 



a, Terminal portion of branch of Spliacelaria cirrhosa : b, 

 lateral branchlet of & tribuloides, the terminal cell of which is 

 emitting antherozoids. 



