THE WAY IN WHICH NEW PLANTS ARISE 145 



sporophyte often grow into sporophytes upon ger- 

 mination. This is found in mushrooms and moulds. 

 The mould which grows upon moist bread develops 

 small sacs filled with spores, which take a black or 

 brown color when ripe. These spores germinate 

 and grow individuals exactly like those from which 

 they sprung, without the formation of another gen- 

 eration. The asexual spores of the sporophyte may 

 be observed if the umbrella-like top of a mushroom 

 is carefully taken off and placed on a sheet of white 

 paper for a day or two. The spores which are borne 

 on the thin plates or gills on the under side of the 

 cajj are set free and fall upon the paper in great 

 number. The germination of these generally pro- 

 duces a sporophyte. 



200. The generations of the seed plants. — The 

 species which produce flowers and seeds have two 

 generations, but the gametophyte is so small that 

 its behavior may not be seen without the use of 

 special methods of observation with the compound 

 microscope. 



201. The gametophyte, or egg-hearing generatio7i 

 in the seed plant. — It was shown in the life history 

 of the fern that unlike cells from different parts of 



