SPOROPHYTE 



441 



Sporophyte. The sporophytes are delicate plants with leafy 

 much branched stems (Fig. 393). The strobili 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 (ra) 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 (TO) (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. 



