ics and to try to make some order from the rather chaotic 
state which at present obtains. A survey of the literature 
has been made, and the information from this source is 
evaluated in the light of field experience in the north- 
western part of the Amazon Valley which seems to be 
the centre of use of these narcotics. It is noteworthy that 
such a standard work as Hartwich (29) fails even to men- 
tion any intoxicant from the Malpighiaceae. 
This present study, however, leaves much to be de- 
sired. Since references to the malpighiaceous narcotics 
are widely scattered throughout botanical, anthropologi- 
cal, geographical and travel literature, I can make no 
claim to completeness of coverage. By far the greatest 
number of the references in regard to the sources of these 
narcotics are of limited or doubtful value; nevertheless it 
has been thought best to cite all that have come to light. 
I might say categorically, however, that much careful 
and sustained field work must be done before anything 
approaching a full understanding of the problem may be 
attained. 
Since this paper is concerned only with the identifica- 
tion of source-species, all discussion of the uses, effects, 
chemical constitution and ethnological importance of the 
narcotics themselves has been omitted. 
The line drawings were made possible by a grant from 
the American Academy of Arts and Sciences, and pub- 
lication of the illustrations has been done through a grant 
from the National Science Foundation. I express my 
appreciation to Miss Ruth Barton and Mr. Elmer W. 
Smith for the drawings reproduced herein. 
II] 
When, in 1851, the botanical explorer Richard Spruce 
penetrated the upper Rio Negro basin in Amazonian 
Brazil, a new and fertile epoch opened for natural science 
[2] 
