REPRODUCTION AND DEVELOPMENT 



253 



without being fertilized. True spores are produced among animals 

 only by Protozoa. The green moss plant is a sexual generation 



PROTONEMA 



GERMINATING 

 SPORE 



Fig. 173. — Diagram of the life cycle of a common moss. 



which never reproduces itself but always produces an asexual 

 generation from its fertilized tgg. The parasitic asexual generation 



