SPOROPHYTE 



441 



Sporophyte. — The sporophytes are delicate plants with leafy 

 much branched stems {Fig. 393). The strobiU occur on the ends 

 of the branches, and the sporophylls somewhat resemble the foli- 

 age leaves, but are usually smaller and more compact {Fig. 394). 



One notable feature is that there are two kinds of spores pro- 

 duced. In Bryophytes, True Ferns, Horsetails, and Lycopo- 



me 



Fig. 394. — The vegetative and spore-bearing structures of the sporo- 

 phyte of Selaginella. A, a shoot of Selaginella, showing the stem, vegetative 

 leaves, and the strobili (st) at the ends of the branches (X 2). B, a micro- 

 sporophyll, showing the microsporangium (m) which has opened to allow the 

 microspores to escape (X about 10). At the right of the microsporophyll 

 are shown two microspores (s) (X 50) . C, megasporophyll with megasporan- 

 gium (me) open, thus exposing the four megaspores and permitting the micro- 

 spores to come in contact with the megaspores. Below the megasporophyll 

 are shown two megaspores (n) (X about 20). D, lengthwise section through 

 a portion of a shoot, showing the position of the two kinds of sporangia in 

 relation to the leaves, and also the relative sizes of the two kinds of spores 

 (X 15). Partly from Dodel-Port and partly from nature. 



