Simple Plants Without Chlorophyll — Fungi 175 



Sexual reproduction in Saprolegnia occurs by developing enlarged 

 oogonia (o -ogo' ni a) (Gr. oon, egg] gonos, beget) and clublike, male 

 antheridia (an ther -id' ia) (Gr. anthos, flower; idion, diminutive). 

 Each oogonium contains eggs. The antheridia penetrate the oogonia 

 and discharge male nuclei through antheridial tubes. An egg fertilized 

 by a male nucleus forms a zygote which develops a new hypha. In 

 Saprolegnia the same plant produces the antheridia and oogonia (mo- 

 necious). 



B. Class Ascomycetes (ask o my -ce' tez) (Gr. askos, sac; mykes, fungus) 



1. Penicillium (pen i -sil' i um) (L. penicillus, painter's brush). — 

 This blue-green mold has a loose mass of hyphae which grows on, or in, 

 such materials as damp leather, foods, citrus fruits, etc. The spore-bear- 

 ing hyphae are called conidiophores (ko -nid' io for) (Gr. konis, dust; 

 idion, diminutive; pherein, to bear), the tips of which resemble tiny 

 brushes, bearing chains of colored spores (conidia) at the tips (Figs. 39 

 and 73 ) . The spores are very small, light in weight, and usually present 

 in the air. 



Penicillium is classed as an Ascomycete because certain hyphae may 

 produce ascos pores (ask'ospor) (Gr. askos, sac; sporos, spore or seed) 

 within saclike asci. 



Species of Penicillium are responsible for food spoilage and destruction 

 of paper, leather, lumber, etc. Penicillium camemberti and P. roqueforti 

 impart the flavors and odors to these common types of cheeses. The 

 bluish-green areas in the cheese are masses of conidia. P. notatum is 

 widely used as a source for the bactericidal antibiotic penicillin (pen i- 

 sil'in). Antibiotics (an ti bi -ot' ik) (Gr. anti, against; bios, life) are 

 organic substances which are synthesized by one type of organism and 

 which inhibit, or destroy, another type "of organism. This common an- 

 tagonistic inhibition between two species of organisms (especially fungi) 

 is called antibiosis (an ti -bio' sis) . In 1940, the possible medical use of 

 penicillin and other antibiotics in the destruction of pathogenic bacteria 

 was suggested. Since then, numerous antibiotics, such as streptomycin, 

 tyrothricin, Chloromycetin, aureomycin, and many others, have been 

 isolated. These and others are considered elsewhere in the text. 



2. Aspergillus (as per -jil' us) (L. aspergere, brush). — This blue-green 

 mold is composed of a loose mass of hyphae growing on or in damp foods, 

 leathers, fabrics, fruits, etc. The spore-bearing hyphae are called conidio- 

 phores which produce chains of colored spores (conidia) on the enlarged, 



