68 



LECTURE V. 



lateral outgrowths, not only roots but also the proper shoots of the Moss, which in 

 their turn are the bearers of the sexual organs ; the protonema may thus be looked 

 upon as a simple preliminary stage of the whole vegetative body of the Moss. The 

 leaf-like plates of tissue, abounding in chlorophyll, which sometimes occur on the 



Fig. 6%.—Funarüi liygrometrica. A germinating spores ; w vacuole ; -w root ; s exosporium ; H part of a 

 developed protonema, about three weeks after germination ; h a prostrate main shoot, with brown walls and oblique ' 



septa, from which erect branches proceed ; K rudiment of a leaf shoot, with root iv (..4 x 55° i ^ ^ about go). 



protonema, but which cannot be regarded as leaves in the narrower sense of the 

 word {Teiraphis), also deserve special mention. Like numerous similar structures 

 in the Algae, Liverworts, and even the prothallia of the Ferns, we have here to do 

 with shoot-formations which, like the cladodes of vascular plants, serve essentially 



Fig. 64.— Protoneraatous outgrowth from the root of Mnittnt koritnm, with leaf-forming buds fC, 

 roots of an inverted sod, from which the protonema filaments (« «) shoot forth (X90) ■ 



only the purpose of presenting a larger quantity of chlorophyll to the light, and so 

 aid nutrition. 



In some subdivisions of the Liverworts we meet with flat broad shoot-axes, 

 which, provided with rhizoids on their under sides, either possess leaf-like mem- 

 branes or entirely dispense with them : this, however, from our point of view, does 



