292 Field, Forest, and Wayside Flowers 



So the prothalli of the selaginella are male and 

 female, and they spend their brief lives attached 

 to their respective spores, and almost completely 

 enclosed by them. 



The gymnosperm represents the next phase of 

 plant-history. For the sturdy pine-tree, like the 

 little moss-like selaginella, has two prothallus 

 parents, both tiny and short-lived, The selaginella 

 prothallus which lives in the smaller or ' 'micro "- 

 spore is minute, though the one which develops 

 in the larger or " macro "-spore comes a little way 

 out into the world, and in some species grows 

 large enough to be seen with a pocket-lens. But 

 neither of the prothallus parents of the pine can 

 be seen without the aid of a high-power micro- 

 scope, and they never leave the spores in which 

 their lives begin. 



The larger or female prothallus is completely 

 enclosed by the macrospore, and the macrospore 

 is developed inside the ovule, and stays there dur- 

 ing its entire life. This prothallus is only a little 

 mass of cell-tissue, almost colorless, because it 

 lives in the dark. After it has ''got its growth" 

 tiny archegonia are formed in it, and these stand 

 in such a position that their flask-mouths open 

 toward that spot in the ovule which is not 



