straight at my hand, and, catching two of my fingers round with its fore
legs, administered a hug so sudden and violent as to cause an acute
sensation of pain; then, at the very instant I experienced this feeling,
which made me start back quickly, it released its hold and bounded out
and away. I flew after it, and barely managed to overtake it before it
could gain the water. Holding it firmly pressed behind the shoulders, it
was powerless to attack me, and I then noticed the enormous development
of the muscles of the fore legs, usually small in frogs, bulging out in
this individual, like a second pair of thighs, and giving-it a strangely
bold and formidable appearance. On holding my gun within its reach, it
clasped the barrel with such energy as to bruise the skin of its breast
and legs. After allowing it to partially exhaust itself in these
fruitless huggings, I experimented by letting it seize my hand again,
and I noticed that invariably after each squeeze it made a quick,
violent attempt to free itself. Believing that I had discovered a frog
differing in structure from all known species, and possessing a strange
unique instinct of self-preservation, I carried my captive home,
intending to show it to Dr. Burmeister, the director of the National
Museum at Buenos Ayres-Unfortunately, after I had kept it some days, it
effected its escape by pushing up the glass cover of its box, and I have
never since met with another individual like it. That this singular
frog has it in its power to seriously injure an opponent is, of course,
out of the question; but its unexpected attack must be of great
advantage. The effect of the sudden opening of an umbrella in the face
of an angry bull gives, I think, only a faint idea of the astonishment
and confusion it must cause an adversary by its leap, quick as
lightning, and the violent hug it administers; and in the confusion it
finds time to escape. I cannot for a moment believe that an instinct so
admirable, correlated as it is with the structure of the fore legs, can
be merely an individual variation; and I confidently expect that all I