MORPHOLOGY AND RELATIONSHIPS OF MICROORGANISMS 43 



into the air away from the moist surface of the medium in which 

 they are growing. This facilitates their dispersal by the air 



Fig. 23. Types of the spores and the spore-bearing organs of the molds 

 1, Sporangium of the Mucor: a, columella; 6, sporangiophore; c, spores; d, 

 sporangium wall. 2, Sporangia of Sporodinia: a, sporangiophore; 6, sporangia 

 containing spores. 3. Ascus of an ascomycete, Peziza: a, ascus or spore sac; 

 6, spore; c, sterile threads or paraphyses. 4, Oi'dium spore formation; the t 

 hyphse are segmenting to form spores or oidia. 5, a, Chlamydospores formed 

 in the hypha of a Chlamydomucor. 6, Zygospore of a Mucor: a, hypha; 6, 

 suspensor; c, zygospore. 7, Conidiophore and conidia of Penicillium: a, con- 

 idiophore; 6, verticillate branches of the conidiophore; c, chains of spores or 

 conidia. 8, Aspergillus: a, conidiophore; 6, inflated tip of the conidiophore; c, 

 sterigmata; d, chain of spores. 9, a, Hypha; 6, poorly differentiated conidio- 

 phore; c, chain of conidia. 



currents. When they fall upon a suitable medium they ger- 

 minate and soon develop the typical mold plant. 



MORPHOLOGY OF THE PROTOZOA 



The protozoa are unicellular and bear much the same relation 

 to the higher animals or metazoa that the bacteria do to the higher 

 plants. Notwithstanding that they are reckoned among the 

 simplest forms of life, they are, nevertheless, greatly diversified 

 in shape, size, and structure. Only the barest outline of their 

 structure can be given here. For a more detailed account the 

 student is referred to the section on Protozoa. 



