BltYOPUYTES 303 



duces only sexual spores (oospores), and therefore produces 

 sex organs and gametes. It is known, therefore, as the 

 fjniin'tdpliijte — that is, " the gamete plant." 



The generation which consists of the " sjiore fruit " — 

 that is, leafless stalk and spore case — produces only asexual 

 spores, and is called the ^jiurnphtitf — that is, " the spore 

 plant." 



The relation lietween tlie two alternating generations 

 may be indicated clearly by the following formula, in 

 which G and S are used for gametophyte and sporophyte 

 respectively : 



G—O o~S— o— G— 8> o— S— 0— G, etc. 



The formula indicates that the gametophyte produces 

 two gametes (sperm and egg), which fuse to form an oosi)ore, 

 which produces the sporophyte, which produces an asexual 

 spore, which produces a gametophyte, etc. 



In reference to the sponipliytes and gametophytes of 

 Bryopliytes two peculiarities may be mentioned at this 

 point: (1) the sporophyte is dependent upon the gameto- 

 phyte for its nourisliment, and remains attached to it ; (2) 

 the gametophyte is the special chlorophyll-generation, and 

 hence is the more conspicuous. 



If the ordinary terms in reference to Mosses be fitted 

 to the facts given above, it is evident that the " moss 

 plant" is the leafy branch of the gametophyte; that the 

 '' jnoss fruit " is the sporophyte ; and that tlie alga-like 

 part of the gametophyte has escaped attention and a 

 common name. 



The names now given to the different structures which 

 appear in this life history are as follows : The alga-like })art 

 of the gametophyte is the protoiiema, the leafy branch is 

 the ^rt;;(p/o/)//(07' ("gamete-bearer"") ; the -whole sporophyte 

 is the sjioriKjtmi II II) (a mime given to this peculiar leafless 

 sporophyte of Bryophytes), the stalk-like portion is the .y(';'(/, 

 the part imliedded in the gametophore is the foot, and the 

 urn-like spore-case is the cdjjsiih'. 



