34 PAEASITES BELONGING TO THE GENUS GLOIMEEELLA. 



November 23 an abundance of white mycelium was present in the 

 cultures, also a number of black patches looking like areas of develop- 

 ing perithecia. On December 9 a flask of corn meal in which a sub- 

 culture had been made from a potato plug showed an abundance of 

 mature perithecia with asci and ascospores, which appeared identical 

 with those of the Glomerella from other hosts. 



On December 13 three plates were poured, using ascospores from 

 the flask culture just described. On December 19 all the plates 

 showed perithecia and also conidia. 



On January 4 other plates* were poured from the same material 

 apparently containing ascospores only. Conidia developed in a few 

 days, and perithecia also appeared later. 



On January 23 subcultures were made in flasks of corn meal. On 

 February 9 an abundance of perithecia and mature asci were present. 

 Very few conidia were found. The fungus used in all these cultures 

 appeared to belong to a race in which the perithecial form predomi- 

 nated. So far as known, no organism belonging to this group has 

 heretofore been described or reported from the ginkgo. Plate II, 

 figures 27 and 27a, shows an ascus and ascospores from leaves of this 

 host. 



GLEDITSIA TRIACANTHOS L. (HONEY LOCUST). 



Glomerella cingulata (Stonem.) S. and v. S. 



On November 24 cultures in flasks of corn meal were made by trans- 

 ferring conidia from an acervulus on a leaf taken from a locust tree 

 on the grounds of the Department of Agriculture. A little leaf tissue 

 was also included in this transfer. On December 1 all of the cultures 

 were identical in appearance and showed an abundant growth of 

 young perithecia of Glomerella with asci but no fully mature asco- 

 spores. No acervuli or conidia were seen. On December 9 there was 

 an abundance of mature perithecia and ascospores present. No dis- 

 tinct acervuli or conidia were positively identified in these cultures, 

 though the cultures were derived from conidia or conidia-bearing 

 mycelium from the leaf of the host. On January 4 poured plates were 

 made, using ascospores from the flask cultures just mentioned. These 

 ascospores germinated readily and produced a growth of the usual 

 appearance. On January 8 conidia were found in these cultures. 

 On January 10 two more plates were poured, using ascospores from 

 the same cultures. These spores germinated, and on January 15 

 perithecia were found at many points in the plates. This strain also 

 showed a great predominance of perithecia. In other respects it 

 appeared identical with the Glomerella from other hosts. An ascus 

 and ascopores from cultures from this host are shown in Plate II, 

 figures 20 and 20a. 



252 



