DEVELOPMENT OF PYCNIDIA AND ACERVULI 381 



1. Pycnidia discoid, cupulate, or hysteroid, sometimes opening irregu- 

 larly Discellaceae (Excipulaceae) 



The Aloniliales are constituted of 4 families, distinguished as 

 follows: 



1. Hyphae, conidiophores, and conidia hyaline or cottony 



Moniliaceae (iMucedinaceae) 



1. Hyphae, conidiophores, and conidia typically brown or dark 



Dematiaceae 



1. Conidiophores aggregated into a cyhndric fascicle or synnema 



Stilbaceae 



1. Conidiophores compacted, forming a globose, cushion-shaped, or 

 cylindric structure, a sporodochium, bearing conidia at the upper 

 surface. Tuberculariaceae 



The single family Alelanconiaceae of the Order Alelanconiales 

 includes all imperfect fungi having acervular fruiting bodies, and 

 the Alvcelia Sterila are not subdivided. 



Within each family further groupings are made by employing 

 color, shape, and septation of conidia as the bases for these 

 groupings, as follows: 



Amerosporeae: conidia 1-celled, spherical, ovoid, elongated, "or allantoid. 



Hyalosporeae: conidia hyaline. 



Phaeosporeae: conidia colored. 

 Didymosporeae: conidia 2-celled. 



Hyalodidvmae: conidia hyaline. 



Phaeodidymae: conidia colored. 

 Phragmosporeae: conidia transversely 3- or more-celled. 



Hyalophragmiae: conidia hyaline. 



Phaeophragmiae: conidia colored. 

 Dictyosporeae: conidia divided by transverse and longitudinal septa. 



Hyalodictyae: conidia hyaline. 



Phaeodictyae: conidia colored. ' 



Scolecosporeae: conidia filamentous, thread-like, 1- to several-celled. 

 Helicosporaeae: conidia coiled, 1- to several-celled. 



Staurosporeae: conidia radiately lobed or star-shaped, non-septate or 

 septate. 



Development of pycnidia and acervuli. Few studies have 

 been devoted primarily to the origin and development of pyc- 

 nidia and acervuli. Incidental observations by a number of 

 workers, how^ever, in connection with a particular species have 

 revealed that all species conform to one or the other of two essen- 

 tial types. These t)^pes de Bary long ago designated "meristog- 

 enous" and "symphogenous." If the primordium of the fruiting 



