THE MORPHOLOGICAL COMPOSITION v)F PLANTS. 49 



ing separation to be arrested ; and the fructifying elements 

 will revert towards the ordinary form, and develop in con 

 nexion with the parent. Turning to the Acrogens, we 

 tind among them, many indications of this transition from dis 

 continuous development to continuous development. Thus the 

 Liverworts give origin to new plants by cells which they 

 throw off from their surfaces ; as, indeed, we have seen that 

 much higher plants do. &quot; According to Bischoff,&quot; says 

 Schleiden, &quot;both the cells of the stem (Jungermannia biden- 

 tata) and those of the leaves (/. cxsccta) separate themselves 

 as propagative cells from the plant, and isolated cells shoot 

 out and develop while still connected with the parent plant 

 into small cellular bodies (J. violacea), which separate from 

 the plant, and grow into new plants, as in Mnium androgyimm 

 among the Mosses.&quot; Now in the way above explained, these 

 propagative cells and proliferous buds, may continue de 

 veloping in connexion with the parent, to various degrees 

 before separating ; or the buds \vhich are about to become 

 fructifying organs, may similarly, under increased nutrition, 

 develop into young fronds. As Sir AY. Hooker says of the 

 male fructification in Jungermannia fur cata, &quot; It has the ap 

 pearance of being a young shoot or innovation (for in colour 

 and texture I can perceive no difference) rolled up into a 

 spherical figure.&quot; On finding in this same plant, that some 

 times the proliferously-produced frond, buds out from itself 

 another frond before separating from the parent, as shown in 

 Fig. 46 ; it becomes clear that this long- continued connexion, 

 may readily pass into permanent connexion. And when 

 we see how, even among Pha3nogams, buds may either detach 

 themselves as bulbils, or remain attached and become shoots ; 

 we can scarcely doubt that among inferior plants, less de 

 finite in their modes of organization, such transitions must 

 continually occur. 



Let us suppose, then, that Fig. 73 is the frond of some 

 primitive Acrogen, similar in general characters to Junger- 

 &quot;iiannia epiphylla, Fig. 43 ; bearing, like it, the fructifying buds 



