QSARACB^. 331 



Carolina thirty-eigUt edible speiies of Agarieus, eleven of Boletus, nine 

 of Polyporus, seven of Hydnum, and tUirteen of Clavaria. 



(/) Polypori'es Bowmani of the Carboniferous is tlie oldest known 

 member of this order. In the Tertiary the modern genera Lenzites, 

 Polyporus, and Hydnum are represented. 



§ V. Class Ohabacb^. 



430. — In this small group of chlorophyll-bearing aquatic 

 plants the sexual organs, while still preserving essentially 

 the structure common to other Carposporese, present con- 

 siderable modifications. The female organ consists of a 

 " central cell " or carpogonium (Fig. 337, c), which is the 

 terminal one of a row of cells («, 

 b, c, Fig. 237). From the basal 

 cells there grow out five elongat- 

 ed cells {d, d, Fig. 337), which 

 take an upward direction and 

 surround the carpogonium ; they 

 cohere laterally, so as to form a 

 complete covering. The top of 



.,■ , . T, i.T, I, I^g- 327.— Development of the 



this envelopmg sneatn becomes carpogonium of muua jiexius, 



modified into a projecting crown |^a°mrtio"'t' fe^f e"a\?r'^ge" 



of five (or by division ten) more l^^^'trST^J^ :^FXti\Z 



or less divergent cells {i, i, Fig. '!^^t^^^,li,%%^^^:^^l 



337 B ; and C, Fig. 338, A), "hat later -the enveloping cells, 



' ° ' ' d, d, have almost completely en- 



Fmally, the whole envelope be- closed the central cell, c ,-»,«, ceils 



•' ' . ,1 , 1 which form a crown upon the en- 



comes twisted, so that each en- veioping cells, x aoo.- Aftersachs. 

 veloping cell passes spirally around the carpogonium {A, 

 Fig. 338). 



431. — The male organ, or antheridium, consists of a 

 globular body composed externally of eight spherically tri- 

 angular cells, called the shields, which are united by their 

 zigzag margins (a. Fig. 338, A). From the centre of each 

 shield there projects into the cavity of the antheridium a 

 cylindrical cell (manubrium), and upon each of these there 

 are borne large numbers (twenty to twenty-five) of long 

 coiled and bent many-celled filaments {b and c, Fig. 329). 

 Each fil^ijient cont9,ins from one to two hundred cells. 



