Puslapio vaizdai
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mechanism which enables the serpent to use its poison.

We have in America as venomous serpents the several species of rattlesnake, the water moccasin, the copperhead, and the beautiful coral snake, the little elaps of Florida, too small with us to be dangerous to man.

India is preeminently the home of the poisonous snakes, of which there are no fewer than fifteen genera. The cobra is most abundant, but the Ophiophagus elaps is the most dreaded, and attains at times the length of fourteen feet. Unlike the cobra and the crotalus, this serpent is viciously aggressive, and will pursue a man with activity.

Among the vipers the daboya is entitled to rank as a poisoner close to the cobra, and the crotalida are represented by a number of snakes which are somewhat less effective slayers than the cobra. While these genera are too sufficiently abundant on land, the Indian seas also abound in species belonging to the family of hydrophide. These serpents are agile and dangerous, but as yet no one seems to have made any examination of their venom, nor directly experimented to learn anything of its relative hurtfulness. Poisonous water-snakes are found in abundance on the shores of South America, and used to be

VOL. XXXVIII.-66.

thrown up in numbers into the paddle-wheel covers of the old side-wheel steamers. I never had the good luck to get a living specimen.

The centipede and the scorpion rank high in the popular mind as poisoners, but they are gentle apothecaries compared to the serpent.

We are in America the privileged possessors of the only other animal at all approaching the poisonous snakes in lethal vigor: it is a lizard, the Gila monster (Heloderma suspectum) of Arizona. This strange creature is the only poisonous lizard known. I have heard of but one death in man from its bite, and for a long while it was looked upon by all except the Indian as harmless. Sluggish, inert, well armored with a tough, defensive skin, a feeder on birds' eggs and on insects, it is most difficult to induce this good-humored and most hideous reptile to bite at all. When once it takes hold, no bulldog could be more tenacious. The odor of its poisonous saliva is exactly like that of magnolia buds. Its bite causes no local injury, and its venom is a deadly heart poison.

All of the great family of thanatophidiaæ have substantially the same mechanical arrangements for injecting their venom. When not in action the two hollow teeth known as fangs lie pointing backwards, wrapt in a loose

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which is ordinarily employed to close the mouth by lifting the lower jaw, to which it is made fast. A little circular muscle around a part of the duct keeps it shut and prevents waste of venom.

Let us observe what happens when the rattlesnake means mischief. He throws himself into a spiral, and about one-third of his length, carrying the head, rises from the coil and stands upright. The attitude is fine and warlike, and artists who attempt to portray it always fail. He does not pursue, he waits. Little animals he scorns unless he is hungry, so that the mouse or the toad he leaves for days unnoticed in his cage. Larger or noisy creatures alarm him. Then his head and neck are thrown far back, his mouth is opened very wide, the fang held firmly erect, and with an abrupt swiftness, for which his ordinary motions prepare one but little, he strikes once and is back on guard again, vigilant and brave. The blow is a stab, and is given by throwing the head forward while the half-coils below it are straightened out to lengthen the neck and give power to the motions which drive the fangs into the opponent's flesh; as they enter, the temporal muscle closes the lower jaw on the part struck, and thus forces the sharp fang deeper in. It is a thrust aided by a bite. At this moment the poison duct is opened by the

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air, doing no harm. I had a curious experience of this kind in which a snake eight feet six inches long threw a teaspoonful or more of poison athwart my forehead. It missed my eyes by an inch or two. I have had many near escapes, but this was the grimmest of all. An inch lower would have cost me my sight and probably my life.

A snake will turn and strike from any posture, but the coil is the attitude always assumed when possible. The coil acts as an anchor and enables the animal to shake its fangs loose from the wound. A snake can rarely strike beyond half his length. If both fangs enter, the hurt is doubly dangerous, because the dose of venom is doubled. At times a fang is left in the flesh, but this does not trouble the serpent's powers as a poisoner, since numberless teeth lie ready to become firmly fixed in its place, and both fangs are never lost together. The nervous mechanism which controls the act of striking seems to be in the spinal cord, for if we cut

striking, and they have been on the whole much maligned.

Any cool, quiet person moving slowly and steadily may pick up and handle gently most venomous serpents. I fancy, however, that the vipers and the copperhead are uncertain pets. Mr. Thomson, the snake keeper at the Philadelphia Zoological, handles his serpents with impunity; but one day having dropped some little moccasins a few days old down his sleeve while he carried their mamma in his hand, one of the babies bit him and made an ugly wound. At present the snake staff is used to handle snakes.

I saw one October, in Tangiers, what I had long desired to observe - a snake charmer. Most of his snakes were harmless; but he refused, with well-acted horror, to permit me to take hold of them. He had also two large brown vipers; these he handled with care, but I saw at once that they were kept exhausted of their venom by having been daily teased

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It has followed in man within a minute, but unless the dose given be enormous, or by chance enters a vein, this is very unlikely. The bite is, however, popularly believed to be mortal, and therefore every case of recovery gives credit to some remedy, for it is a maxim with physicians that the incurable and the easily relievable maladies are those which have most remedies assigned to them.

Usually the animal struck gives a cry, and very soon becomes dull and languid. The heart, at first enfeebled, soon recovers, the respirations become slower and weaker and more weak, paralysis seizes the hind legs, the chest becomes motionless, and at last death follows, usually without convulsions. Observe how little this tells us. Mere outward observation gives us but slight explanatory help. If the animal should chance to survive over a halfhour, the part bitten swells, darkens, and within a few hours the whole limb may be soaked to the bone with blood, which has somehow gotten out of the vessels and remained fluid in place of clotting. What is at first local by and by becomes general, and soon the blood everywhere ceases to have power to coagulate. Then leakages of the vital fluid occur from the gums or into the walls of the heart, the lungs, brain, and intestines, and give rise to a puzzling variety of symptoms, according to the nature of the

organ thus disordered. These phenomena make the second stage of poisoning, and with them there is, in finally fatal cases, a continuous and increasing damage to the nerve centers that keep us alive by energizing the muscles which move the chest walls and so give rise to the filling and emptying of the lungs.

When a physiologist speaks of a nerve center he means by this a group of minute nerve cells, and such a group he is apt to call a ganglion, labeling it with the name of the distant organ or the function to which it gives energy. Much alike in appearance, one ganglion keeps the chest in motion, one influences the heart, one regulates the temperature of the body. When we throw into the circulation a poison, it comes into contact with all of these numerous governing centers; but it does not trouble all of them alike. It has, as a rule, a fatal affection for one only, or far more for one than for another. Why venom should, as if by choice, almost instantly enfeeble the ganglia which keep us breathing, none can say. By and by it also in turn disturbs other groups of nerve cells, but its deadliest influence falls on the respiratory mechanism. The nerve cells thus attacked undergo no visible change; yet some mysterious alteration is present. Probably they lose power to give out their waste products and to re-absorb from the blood the material needful to sustain their local life and activity. At

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