LABORATORY AND TEACHING METHODS 64T 



Dry-rot. 



Soft-rot (Gangrene). 



Black-rot. 



White-rot. 



The incidental or experimental evidence of disease is indicated by marks or 

 signs. Such signs are usually afforded by the fruiting or vegetative part of the 

 pathogenic organism. Such terms as mildew, mould, ooze, rust and smut are indica- 

 tive of diseased or parasitic conditions. 



General Suggestions. — In the report which is made by each student following 

 the above outline, drawings should, as far as possible, accompany the descriptions. 



ETIOLOGY 



Common Name of Pathogen. 



Scientific Name. 



Family. 



Pathogenicity. 



Additonal Data. 



Cultural Character of Organism. 



Note. — In case the pathogenic organism is bacterial the directions for its 

 study have already been given as recommended by the Society of American Bac- 

 teriologists. As the outline of the Society is the outcome of years of study, it 

 should be followed in all cases, but in addition the following directions for the study 

 of parasitic plant organisms should be kept in view by the mycologic student. 



Isolation of organism in pure culture. Directions have been given for the manu- 

 facture of culture media and for the isolation of fungi in pure culture. These should 

 be followed. 



Inoculation of pure culture into healthy host plants. 



Recovery of organism in pure culture. 



life history 



The Primary Cycle. — Nature of mycelium (septate, or unseptate; presence or 

 absence of haustoria (nature); intercellular, or intracellular hyphae; color; contents; 

 penetration and destruction of host cells = pathogenic histology of host). 



Kinds of spores (sexual or non-sexual; conidia; pycnospores; oidiospores; 

 chlamydospores; ascospores; zygospores; oospores; urediniospores; teliospores; 

 aeciospores; basidiospores, etc.). 



Sizes, shapes and color of spores. 

 Importance in life cycle. 

 Pathogenesis of primary stage. 

 Saprogenesis. 



The Secondary Cycles. — The same order of procedure should be observed in the 

 study- of the secondary cycles as in the examination of the primary. 

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