136 MARINE SCIENCE 
extracted from certain red seaweeds—Chondrus crispus, or Irish 
moss—appears to be effective in the treatment of stomach ulcer. 
Utilization of these, and discovery of other medically important sub- 
stances is possible, but only. if research is carried out to reveal more 
knowledge about them and the circumstances under which they are 
produced. . 
Some marine animals harbor no enteric bacteria. Whether this 
is due to production of antibiotic or lysing agents by the digestive 
tissues is not at present known, but if 1t could be determined, the in- 
formation might have implications for treatment of bacterially caused 
digestive ailments in man. 
The Cuatrman. Are there not a lot of folk medicines, like seaweed 
and things of that kind, for stomach disorders? I know’ there are’ in 
Japan. 
Dy. Ray. There is. And in the South Pacific islands, where peo- 
ple are closely associated with the sea. That information has been 
picked up and passed from generation to generation, as well as im- 
formation about this second point, the harmful substances. 
2. Many marine forms produce substances of astonishing virulence 
and toxicity toman. Examples of this are: the toxin of the notorious 
red-tide organism Gonyaulax which causes paralytic shellfish poison- 
ing and is several times more toxic than the most poisonous nerve 
gases now known; the snail Conus whose sting can kill a man; the 
poisonous sea cucumbers and sea urchins, found mainly in tropical 
waters, that are lethal to fishes and are capable of causing severe 
disturbances in man; the sting ray and stone fish; the edible fishes 
whose flesh contains a virulent toxin, but only at some times and only 
in some geographical area. 
There are at least three only partly related reasons for interest in 
exotic toxins. The first is of course to find effective antidotes and 
to learn how to use toxins as pesticides in a controlled fashion. The: 
second is the experimental study of toxins and their actions for the 
information this may reveal about basic physiolgical mechanisms. 
For example, study of the plant poison, curare, which has a specific 
action in blocking the passage of stimuli from nerves to muscle, has 
revealed much about the way nerve impulses are transmitted across 
this important juncture. Knowledge of the action of curare has also 
made it possible to use this potent poison safely in some surgical pro- 
cedures. 
Sea cucumbers produce a somewhat similar substance, called Holo- 
thurin, that has the same general action, but is many times more 
powerful. There are studies going on now trying to determine the 
chemical identity of this substance and to see whether it can be modi- 
fied in various ways to control the specific action and make it also a 
useful substance. We know, at the present time, next to nothing about 
the possibility of its use. — 
Study of the wide variety of toxins produced by marine animals 
promises to add enormously to medical knewledge; only very recently 
has medical research recognized the potentiality of marine invertebrate 
pharmacology. . . . tor 
That the same species of fish may be edible in one geographical 
locality and lethally poisonous in another has now been established: 
with certainty. To a lesser degree the same is true for many species 
