HEP A TTCM 



34? 



by the rapid growth of the surrounding tissue of the thallus 



(A, B, and G, 



Fig. 232). In 



other eases the 



antheridia are de- 



veloped in great 



numbers upon 



special branches, 



as in Marchantia, 



which has a large 



" antheridial disc" 



(A and B, Fig. 



231, hu), in whose 



upper surface are 



to be found many 



imbedded anther- 



idia. That the an- 



theridia are actu- 



ally external in 



this case also, be- 



coming apparent- 



ly internal by the 



growing up of the 



surrounding tis- 



sues, is well shown 



in Fig. 233. In 



still other cases 



(e.g., in Junger- 



the 



. 



are in 



,i 



OI tne 



In > o v/1 nnn-n ,. nec - -i tne 8ame wen niatnre and reay for fertliza- 

 leaves, and OCCUr t ion. VL, the base of a fertilized archegonium, the 

 ><i no-Ivor in ornmvj germ-cell, /, divided into two cells by a diagonal partition. 

 blllgiy 01 m groups. ^ /7 late j gta of the game> 8howln a farther division of 



,i .| 



tlie axils 



.Fig. 235. The archegonin, and origin of the sporogo- 

 imm otJfarc/umtia pofymarpha. T. and //., young arche- 

 gonia ; , germ cell ; si, lowest cell of axial row of cells. 

 ///. and IV., the same after the formation of a central 

 canal by the absorption of the axial row of cells in the 

 neck - V-i tne 8ame when niatnre and ready for fertiliza- 



453. The 



, ater stage of the 

 ar _ the germ-cell, / v and the ^bt 



fog 



aing of the growth of a 



perianth, pp. VIII., still later stage of the same, the 

 first Perianth, pp, now enclosing the archegonium; x, the 

 withered neck of the archegonium. IX., the unripe eporo- 

 appears as a simple gonium, enclosed in the old walls of the archegonium. 



low called the calyptra, 



papilla, Composed st, the short, undeveloped stalk of the gporogoniiim! 



e -in Inside of the sporosroninm are the young elaters arranged 



OI a Single Cell, radially, and between them are the spores. I. to VIII. 



Which, by Sllbdi- X 300;^. about 30.-Alter Sachs. 



vision in various directions, gives rise to a more or less 



