SUMMARY OF FUNGI 51 



ditions which would make it impossible for most plants to 

 grow. 



Histology. Sections show a well defined epidermal cell 

 layer and branched and intertwined hyphse of the fungus. 

 The cells of the alga are spherical and occur in groups or 

 clusters among the hyphse. 



Sections through an apothecium show the asci. Each ascus 

 has eight ascospores, and is surrounded by several paraphyses 

 or hairs. Each spore may germinate and become associated 

 with alga cells to form a new lichen. Asexual reproduction 

 is brought about by soridia or fragments of the thallus 

 separating and developing into typical plants. 

 . 



SUMMARY OF FUNGI. 



Fungi as a group are characterized by the absence of chloro- 

 phyll, therefore, they are dependent on plants and animals 

 for food. Some forms are parasitic, the living plant or host- 

 plant furnishing food for their growth and reproduction. 

 Other fungi are saprophytic', they live upon dead plants or 

 animals or the products formed by plants and animals. The 

 fungi are further characterized by producing a great number 

 of spores. 



The plant body is very variable in structure, size and form. 

 In the Schizomycetes or fission-fungi represented by bacteria 

 the plant body consists of a single minute cell of variable 

 form. 



In the Phycomycetes or Algal-fungi represented by mucor 

 the plant body -consists of multinucleated, branched, inter- 

 twined hyphse, the mass of hyphee making up the mycelium. 

 Reproduction is asexual by means of spores formed in the 

 sporangium and sexual by means of conjugating hyphse, 

 the zygospore differing from the ordinary spore by growing 



