34 BULLETIN 1380, U. B. DEPARTMENT OF AGRICULTURE 
the pycnidial or Aposphaeria stage found on the same leaves as the 
ascigerous or Dothidella stage to be stages of the same fungus 
and regarded it as of little importance and serious only on nursery 
plants. 
In June of the same year V. Cayla suggested the identity of the 
disease described from Para by Griffon and Maublanc with that 
collected in the upper Amazon by ITe and with that described by 
Kuyper from Dutch Guiana. Bancroft reported the disease from 
British Guiana in 1913 and considered it of importance on nursery 
plants only. He sent material (conidial) to Kew. where it was 
described as new under the name of Passalora heveae Massee. In 
1914 Petch suggested the relationship of the pycnidial and conidial 
stages described by Kuyper, Griffon, and Maublanc with Dothidella 
ulei and the probable importance of a disease which can attack 
both old and young trees. He further commented on the identity 
of the organism and its importance in 1015. In a series of studies 
from 1915 to 1917 Stahel demonstrated the identity of the organism 
described from the various regions. On the basis of its relations 
with and differences from the saprophytic genus Melanopsamma he 
renamed the fungus Melanopsammopsis heveae (1915). He re- 
ported that the attacked leaves were destroyed, resulting in the 
death of the tips of the branches. A treatment for the disease was 
given by Stahel in 191G. Borer reported on the disease in Trinidad 
in the same year, stating that the fungus must have been present in 
that island for a number of years but only became epidemic dur- 
ing July, August, and September, owing to certain favorable 
weather conditions at that time of the year. He further stated 
that owing to its importance in Dutch and British Guiana the 
disease must now be considered the most serious trouble of Hevea 
in the American Tropics. 
In 1916 Bancroft published additional observations on the disease 
in British Guiana. He called attention to the probable source of 
the inoculum from II even confusa and one other undetermined 
species in the forest and the wide spread of the disease in the 
colony. He found it less common on the coast, but prevalent in 
areas of large plantations. 
Bancroft again gave an account of the disease in Dutch and 
British Guiana in the following }-ear. He stated that the disease 
was so widespread and existed in such virulent form as to lead 
to the assumption that unless some means was found for its con- 
trol the cultivation of Hevea in Dutch Guiana would soon prove 
unremunerative. The most complete account of the causal organism 
with methods of control is that published by Stahel in 1917 under 
the name Melanopsammopsis ulei. Rands in his report of this year 
emphasizes the importance of the disease and the necessity for its 
control. 
HOSTS 
The fungus apparently attacks all species of Hevea. Owing to 
the fact that Hevea brasuiensis predominates over all other species 
the fungus is naturally conspicuous on that host. Through the 
kindness of the director of the Botanic Museum at Para all the 
Hevea specimens in the herbarium were examined. The fungus 
was found on specimens labeled as follows: Hevea brasiliensis* H, 
