The intoxicating yajé of the Correguahe Indians was 
made by boiling pieces of the trunk itself together with 
the crushed bark of the trunk, but later the stem and 
leaves of a plant which the Indians did not permit him 
to examine were added to the mixture. This brew pro- 
duced, as Claes witnessed amongst the natives, very defi- 
nite narcotic symptoms. It is extremely unfortunate that 
Claes was unable to procure specimens of the leaves and 
stems which were used together with the liana, for we 
now know, from the studies of more recent investigators, 
that the narcotic yaje drink of this region of Colombia is 
sometimes of a more complex preparation than that of 
other parts of the Amazon; that very frequently a non- 
malpighiaceous ingredient may be employed. 
Claes did not offer a botanical determination of yajé 
(68). He mentioned that, according to De Wildeman, 
yajé ‘‘might be’? Prestonia amazonica. There is no speci- 
men of this species in the Rijksplantentuin in Brussels, 
and Claes himself states (68) that he did not obtain ma- 
terial for determining yajé, adding: ‘‘It thus is necessary 
to leave for others the task of collecting materials of the 
definitive classification of the plant.’” Michiels and Clin- 
quart (54), publishing their observations made during 
pharmacological experiments with Claes’ material, sug- 
gested that the stems with which they were working 
appeared to belong to Prestonia amazonica. The French 
pharmacologist, Rouhier, feeling (although apparently 
with no sound basis) that yajé and ayahuasca were one 
and the same thing, but that they might, physiologically, 
act differently, put forth the suggestion that ayahuwasca 
represents Banisteriopsis Caapi, whereas yqjé could rep- 
resent the unknown plant which Claes saw the Corre- 
guahe Indians add to the brew. 
A Colombian chemist, Fischer, was apparently the 
first to isolate a crystalline alkaloid from yajé (22). 
[17 ] 
