3S4 BOTANICAL GAZETTE 



[JUNE 



those obtained from the other types. The great majority of the 

 anthracnoses that have been described belong in this group.' Nearly 

 all those of fruits— and a glance at the Hterature will show that there 

 are scores— and a large percentage of the forms on herbaceous stems 

 seem to belong to this type. The problems concerned and the diffi- 

 culties that confront the investigator become more evident the longer 

 the group is studied. Little more can be done in this paper than to 

 add to our knowledge of the biology and physiology of the forms 

 studied. This type is sharply separated from the others, not only in 

 the characters of the perfect stage, but also in those of the mycelial 



and conidial stages. Nearly always one can recognize this type at 

 a glance. 



Some of the evident characters are as follows: (i) The spores 

 ooze out of the acervuli in pink masses or strings ; so far as has been 

 observed, the spore masses in the Gnomonia and Pseudopeziza types 

 are white, cream-colored, or yellow. This may not be a sure criterion, 

 but it seems to hold in nearly every case. (2) In artificial cultures, 

 especially where nutrition is lacking, and sometimes on the original 

 host, the dark-colored secondary spores or appressoria are developed; 

 in no instance have these been observed in the other types, although 

 they have been carefully searched for. (3) The mycelium in pure 

 culture varies but little in diameter; this separates these forms at 

 least from those of the Gnomonia type. Other minor points that 

 help to place the forms in this group are the rapidity of growth, the 

 presence of small black wefts or crusts of myceHum in the culture 

 medium, and the presence of a dark-greenish pigment in old myceHum, 

 especially on sugar media. The last two characters are not always 

 present, but their frequency makes it advisable to mention them here. 



IMost of the work that has been done on species of Gloeosporium, 

 especially by American botanists, has been done on this group. The 

 papers of Miss Southworth, Miss Stoneman, Clinton, Spaulding 

 and VON ScHRENK, Sheldon, Atkinson, and Shear have dealt 



principally with these forms. 



development 



■historv 



t K AA \ 'jcveiupmeni 01 tnese lorms, nttie neea; 



to be added here. Each goes through the same stages in develop 



