CLASSIFICATION 5 



BLASTOMYCETES-YEASTS. Budding fungi. Character- 

 istic lies in predominant round or elliptical unit; some few form 

 mycelia; division by endospores or budding; important in fer- 

 mentation and in disease. Divided into: 



Saccharomyces. Endospores and budding, fermenters. No 

 mycelia. 



Monilia. Budding. No spores mycelia fermenters. 



Oidia. Budding. No spores mycelia non-fermenters. 



Coccidioides. Spores. No budding mycelia non-fermen- 

 ters. 



HYPHOMYCETES-MOULDS. Mycelium-forming fungus; 

 division by spores, branching, budding, or intercalary division; 

 some bisexual. Divided into: 



Phycomycetes. Mucorinae sometimes bisexual division by 

 grouped spores or segmentation of mycelium. Not important 

 pathologically. Example Mucor. 



Mycomycetes. Asexual forms dividing by spores in a sac 

 or by end organs sexual forms dividing by specially developed 

 cells. Mycelia predominate. Example Aspergillus. 



These are the principal groups of yeasts which can be reasonably 

 well classified. There are others, Microsporon, Trichophy ton, and 

 Sporothrix, that have a decided pathogenic importance but for 

 which a systematic position is not easy to give. They belong 

 probably between the two above classes in that mycelial growth 

 with lateral budding and spore formation are their characters. 



Bacteria that are globular in form are called cocci. 



Cocci that divide in one direction of space and grow in chains 

 are called streptococci (Fig. i). 



Cocci that divide irregularly and form parrs of fours, or irregular 

 groups, are called micrococci. Those of this class that form pairs 

 are frequently called diplococci. 1 When they form fours by divi- 

 sion in two directions, they are called tetrads. But when they 



1 This word is frequently used as if it were a biological term indicating some 

 species identity, e.g., Diplococcus pneumoniae. There is no biological 

 group called Diplococci and the term should be used in a descriptive sense. 

 The cause of pneumonia is now called Streptococcus pneumoniae. 



