476 General Botany 



Sporophyte and asexual reproduction. The oospore germi- 

 nates while still within the archegonium on top of the stem, 

 and produces a slender, stalk-like body. The base of this body 

 grows downward into the parent stem and draws water and 

 nourishment from it. At the top of the stalk a sporangium, 

 or capsule, develops which contains spores. The stalk and 

 sporangium live parasitically on the green, leafy moss plant and 

 constitute the sporophyte generation. 



Summary. The Bryophytes probably present some of the fea- 

 tures that characterized the first land plants. They are com- 

 paratively simple in structure, but they are more differentiated 

 than the green algae. They show (i) tendencies toward the de- 

 velopment of distinct absorptive and photosynthetic tissues; 

 (2) the presence of chloroplasts similar to those of the seed plants 

 in both gametophyte and sporophyte ; (3) the development of 

 intercellular spaces, air pores, and (in the sporophyte) guard cells 

 and stomata ; and (4) a life cycle of two distinct phases, each 

 producing a spore that develops the alternate generation. 



The vegetative plant is the gametophyte, and it is among the 

 Bryophytes that the gametophyte attains its greatest size and 

 differentiation among land plants. 



REFERENCES 



Campbell, D. H. Structure and Development of Mosses and Ferns. The Mac- 



millan Company, New York; 1918. 

 Grout, A. J. Mosses with a Hand-lens. Published by the Author, Brooklyn, 



New York; 1905. 

 Mosses with Hand-lens and Microscope. Published by the Author, Brooklyn, 



New York. 

 Jennings, O. E. Manual of the Mosses of Western Pennsylvania. Published by 



the Author, Pittsburgh, Pennsylvania; 1913. 



