194 COMPENDIUM OF GENERAL BOTANY. 



plished by means of the vegetative protonema (Zweigvorkeime) ; 

 in the latter group occasionally by means of swarm-spores (A. 

 BRAUN, PRINGSHEIM). 



Among Fucoidece sexual reproduction is known in only a few 

 cases. Much is yet to be discovered, though in some respects our 

 knowledge concerning the comparative significance of the phe- 

 nomena of reproduction is quite exact. The difference in the 

 phenomena of reproduction in Fucoidece and Floridece may be 

 readily explained from a teleological standpoint. The spermato- 

 zoids of Fucoideoe have cilia, therefore possess autonomous move- 

 ment, while the fertilizing elements of Floridece (red marine algge) 

 are without cilia, and hence motionless, and are called ' ' spermatia ' ' 

 (o nepua, seed). In perfect harmony with such facts we find that 

 the egg- cell of Fucoidece is first set free and is endowed with 

 autonomous movement, and may be reached by the equally free 

 swimming spermatozoids. Among Floridece fertilization is accom- 

 plished by the female organ (" carpogone ") sending out a hair- 

 like structure (" trichogyne ") from the fixed egg-cell to which 

 the spermatia become attached. Floridece also reproduce asexually 

 by means of ' ' tetraspores ' ' ; these are formed by each mother- 

 cell dividing into four parts (BORNET, THURET, PRINGSHEIM, and 

 others). 



B. FORMS OF REPRODUCTION AMONG FUNGI. 



The following is a brief summary of the chief forms of repro- 

 duction among the fungi. Asexual reproduction predominates. 

 The asexual spores are produced either endogenously or exoge- 

 nously. When exogenous, either basipetally or acropetally on the 

 basidia or immediately on the mycelium. (The exogenous spores 

 are sometimes called oonidia in distinction to the endogenously pro- 

 duced endospores.) 



We will first mention the two groups Zygomycetes and Oomy- 

 cetes in which sexual reproduction usually occurs. As the names 

 would indicate, we have conjugation with the formation of zygo- 

 spores in the former group, and oospore-formation in the latter 

 group. In the genus Mucor endospore-formation also occurs, 

 ("mould" on bread, fruit, old damp clothing, leather, etc., be- 

 longs to Mucor.) Finally, we will mention BREFELD'S chlamy do- 

 spore-formation as an asexual mode of reproduction. By this is 



