BRYOPHYTES 85 



obtain all its food from the gametophyte. If such a sporo- 

 phyte should establish connections with the soil (on which 

 the gametophyte is lying) by means of roots, it would be- 

 come an independent plant, and no longer be a bryophyte. 



Although the sporophyte of Anthoceros has been likened to 

 a small grass-blade in form and color, it is very far from having 

 the structure of a grass-blade, for it is in no sense a leaf. It 

 is a stem-like structure, which has the power of elongating 

 like a stem, and a section across it shows 

 three regions (Figs. 68 and 69) ; (1) a 

 green region on the outside, (2) a spore- 

 producing region next to the green, and 

 (3) a central region of colorless and sterile 

 cells. This is the structure which is 

 thought to have given rise to sporo- 

 phytes with stems and leaves. 



51. The failure of Bryophytes. This 



J r J FIG. 69. Anthoceros: 



does not mean that Bryophytes are cross-section of a spo - 



,, ., ,i i f '. i rophyte, showing the 



failures in themselves, for it has been three regions de- 

 seen that they are abundant enough to esf t'he very distSt 

 be called successful. The failure referred sur [ ace l ?y* T f ce 



is the epidermis. 



to is that the bryophyte plan could not 

 make any further progress leading to higher plants. We 

 infer that this is true, simply because the plan of the higher 

 plants is different. 



A gametophore is developed by many Liverworts and by 

 all Mosses. As the name implies, this stalk carries up the 

 gametes (eggs and sperms) above the general surface of the 

 prostrate body. Since the fertilized egg produces the spo- 

 rophyte with its spore-case, the gametophore certainly puts 

 the spores in a favorable position for dispersal by air. If 

 this position favors the spores, however, it does not favor 

 the sperms which must swim, for they are carried up into a 

 position of least moisture. It is an interesting arrangement 

 that favors spores by interfering with the very act (fertiliza- 

 7 



