and manioc, elevated fish-drugging from a hunting-fishing trait 
alone, to that of a sedentary, agricultural level of economy (11). 
Some fish-poisoning plants have been cultivated so long that 
they are no longer known in the wild. 
Ill 
Whether the toxic plant be called ‘“‘varbasco”’, “‘barbasco”’, 
‘*timbo’’, ‘‘plomos”’ or any number of local names, the purpose 
and technique of fish-drugging are almost identical wherever this 
method of catching fish has been noted. The purpose 
everywhere is to catch a large quantity of fish with the least 
effort and in the shortest time. The technique presupposes not 
only this need but also certain practical knowledge. “The uni- 
versal feature of fish-stupefying is simply the recognition of a 
narcotizing, sometimes lethal effect on the fish by introducing 
the poisonous principle of a plant into the water. An effective 
plant piscicide must fulfill certain conditions, among which are 
solubility, rapid diffusion in the water, and high potency ... and 
it must have such an effect that the fish itself does not have a 
toxic quality when eaten by humans”? (9). Either a pool or a 
sluggish stream is selected for the operation, or a rough dam is 
constructed to make a temporary pool. In either case, an area 
suitable for restricting and concentrating the action of the poison 
and for penning up the fish is essential. 
The toxic principles of piscicides differ. Some are tannins, 
some alkaloids, some glycosides. Whether fish die or are only 
stupefied may depend on the kind of toxin, the strength or 
concentration of the poison, and the size of the fish (17). 
In the most common type of fishing with toxic plant material 
— introduction of crushed vegetal material into the water — the 
animal’s respiratory apparatus is affected, apparently 
paralyzed. Fish rise ‘‘gasping”’ to the surface. There Is also some 
evidence that certain poisons affect the nervous system (9). In 
any case, the result is a stupefying effect followed usually by 
death, unless the fish are able to escape from the poisoned 
water. 
There are various methods for introducing the poison into the 
water. Sometimes, crushed plants or parts of plants (such as 
bark or root only) are thrown directly onto the surface of the 
entire area to be fished. On other occasions, the crushed mate- 
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