62 



PLANT LIFE. 



food stored in the spore from which they originate. The 

 gametoi»hyte of such species lias lost wholly its vegetative 

 character, and is restricted in function to the production of 

 tlie sexual organs. 



71. The sporophyte. — In contrast with the smallness and 

 simplicity of the ganietoph\'te is the relatively large size and 



Fig. 76. — Embryo of /Vtv/V ,?,y /////?/.;, and a small part of the >;ametophyte, ^, in 

 which its foot./", is embedded. 7-, the primary root ; j-, primary stem ; /, primary 

 leaf. Induced growth of the s;ametophyte about the foot is shown by small size and 

 number of cells. Much magnified. — After Hofmeister. 



Fig. 77 — Section through embryo and gametophyte of maidenhaii fern {Adiantttjn 

 Ca/'zllns-l e neris) . I'he embryo is older than that in fig, 76. p^p^ gametophyte; 

 /;, rhizoids. among which are two spermaries. The eggs in three ovaries failed to 

 develop ; the other formed the embryo, R. a, primary stem, only slightly de- 

 veloped (compare ,t, fig 76) ; /', primary leaf ; 7c, primary root. The part embedded 

 in the gametophyte is the foot. IVtagnified about 10 diam.- After Sachs. 



complexity of the sporophyte (fig. 75). It is always differ- 

 entiated into stem and leaves, and, with rare exceptions, 

 roots also. This great advance in the development of the 

 sporophyte of the fernworts, as contrasted with its form in 

 their nearest of kin below, the li\'erworts and mosses, suggests 

 that the fernworts are a very old grouji ; a hint which is con- 

 firmed by the anticjuity of their fossil remains. It is also 

 noteworthy that, as compared with mossworts, the chief work 



