thus (Euphorbiaceae), Clibadium (Compositae), Tephrosia 
(Leguminosae), and Lonchocarpus (Leguminosae). Philoden- 
dron craspedodromum (Araceae) represents a new and local 
fish-poison plant the use of which involves an unusual technique 
not hitherto reported in the literature. The Desana of the Vaupés 
gather the leaves of this aroid and tie them into bundles which 
they leave on the forest floor for two or three days to ferment. 
The leaves are then crushed and thrown into the water. Nothing 
is known of the chemistry of this plant. The same lack of chemi- 
cal knowledge holds for other fish poisons recently discovered, 
such as the bombacaceous Patinoa ichthyotoxica among others 
(2.23). 
Parallels of this process of fermentation of the leaves of 
Philodendron craspedodromum, which may alter the toxins or 
their effects, are found in the preparation of two Old World 
piscicides which are lightly roasted before use (8, 11). One, 
Ophiocaulon cissampeloides, contains free hydrocyanic acid; 
the other, Jagera pseudorhus (Cupana pseudorhus), is cyano- 
phoric. Subjection to gentle heat would seem to be a means of 
heightening the toxic effects, and fermentation might well act 
somewhat similarly. Descriptions of the preparation of Manihot 
esculenta, — which itself can be used as a piscicide — mention 
both heat and soaking as altering its toxicity, due to the presence 
of a cyanogenic glycoside. 
The discovery of new piscicides in the northwest Amazon 
suggests that the focus of origin and dispersal center of their use 
may extend beyond this area. The Orinoco basin with which it 
merges and the tribes of which share culture traits with its 
peoples, may also prove to be significant. Up to the present, 
comparatively little botanical and ethnological explorations 
have taken place along the Middle Orinoco. This possibility, as 
well as that of independent invention, should therefore be con- 
sidered in the drawing of conclusions. 
Plants used as fish poisons may be lianas, bushes, or small 
trees. Depending on age and other conditions, the same plant 
may be all three of these in form. Its effectiveness as a piscicide 
may vary with seasons, since the concentration of the toxic 
constituents may vary not only with location but also with time 
of year. The plants may grow wild or they may be cultivated in 
small plots or even in large plantations called ‘‘barbascales”’ 
(13). Their cultivation, as with certain food plants such as maize 
re, 
