Safford (23,24) doubted that ololiuqui was a member 
of the Convolvulaceae on the basis of negative results in 
pharmacological experiments with the seeds of Rivea 
corymbosa. He suggested that ololiuqui was toloache, 
Datura ceratocaula Hook. (11) or D. meteloides Dunal 
(24), because reports of ololiuqui- or piule-intoxication 
indicated symptoms similar to those common in Datura- 
intoxication. 
Pharmacological work has only recently succeeded 
in proving the presence of an active principle in Pvea 
corymbosa. Santesson (26) has found that piule (ololiuqui 
seeds) contains a gluco-alkaloid which is almost inactive 
physiologically until hydrolysis occurs. This constituent 
fails to give positive alkaloid reactions until, on hydroly- 
sis with hydrochloric acid, the alkaloid is set free and re- 
acts to standard alkaloid tests. Chemical identification of 
this gluco-alkaloid is needed. Although Santesson admits 
that ‘‘ein solcher Korper ist meines Wissens eine Selten- 
heit,’’ the possibility that more such masked alkaloids 
exist in some of these unusual Mexican plant intoxicants 
is not remote. Conditions resembling this exist in the 
glucosides of Digitalis spp. (digitalin) and Strophanthus 
spp. (strophanthin) where the constituents themselves 
are poisonous, but their decomposition products harmless. 
The effects of ololiuqui (piule) had been described (16) 
as not definitely narcotic, but ‘‘hypnotic-somnambulis- 
tic.”” The condition of the subject under piule-intoxica- 
tion is very similar to hypnotism, whence the use of the 
plant by sorcerers. Santesson (26) confirms this with 
pharmacological experimentation on frogs, where partial 
cerebral paralysis results in a sluggish and passive condi- 
tion of the animal, which he calls ‘‘eine Art Narkose, 
oder Halbnarkose. *’ 
There are many medicinal plants in the genus [pom- 
oea (1) with which Rivea corymbosa has close relation- 
[75 | 
