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 
oe 
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 
