Lesson 20

Snake poison

How it came about that snakes manufactured poison is a mystery.
蛇是如何制造毒液的，这还是一个谜。
Over the periods their saliva, a mild, digestive juice like our own, was converted into a poison that defies analysis even today.
在这些时期，他们的唾液——一种像我们自己一样的温和消化液——被转化成了一种即使在今天也无法被分析的毒药。
It was not forced upon them by the survival competition; they could have caught and lived on prey without using poison, just as the thousands of non-poisonous snakes still do.
它并非通过生存竞争被强迫施加于他们；他们本可以不使用毒液而捕获并以猎物为生，正如成千上万的无毒蛇仍然在做的那样。
Poison to a snake is merely a luxury; it enables it to get its food with very little effort, no more effort than one bite.
对于蛇来说，毒液仅仅是一种奢侈品；它使它能够几乎不费力气地获得食物，即不超过一口的努力。
And why only snakes?
而且为什么仅仅是蛇？
Cats, for instance, would be greatly helped; no running fights with large, fierce rats or tussles with grown rabbits—just a bite and no more effort needed.
例如，猫将会受到极大帮助；没有与大型、凶猛老鼠的奔跑打斗，也没有与成年兔子的扭打——只需一口，无需更多努力。
In fact, it would be an assistance to all carnivores though it would be a two-edged weapon when they fought each other.
事实上，这对所有食肉动物都将是一种帮助，尽管当它们彼此战斗时，它将是一把双刃剑。
But, of the vertebrates, unpredictable Nature selected only snakes (and one lizard).
但是，在脊椎动物中，不可预测的自然只选择了蛇（以及一种蜥蜴）。
One wonders also why Nature, with some snakes, concocted poison of such extreme potency.
人们也不禁想知道，为什么自然界在某些蛇类身上调制出了效力如此极端的毒液。
In the conversion of saliva into poison, one might suppose that a fixed process took place.
在将唾液转化为毒液的过程中，人们可能会认为发生了一个固定的过程。
It did not; some snakes manufactured a poison different in every respect from that of others, as different as arsenic is from strychnine, and having different effects.
它没有；一些蛇制造的毒液在每一个方面都与其他蛇的毒液不同，就像砷与士的宁一样不同，并且具有不同的效果。
One poison acts on the nerves, the other on the blood.
一种毒药作用于神经，另一种作用于血液。
The makers of the nerve poison include the mambas and the cobras and their venom is called neurotoxic.
神经毒素的制造者包括曼巴蛇和眼镜蛇，它们的毒液被称为神经毒性的。
Vipers (adders) and rattlesnakes manufacture the blood poison, which is known as haemolytic.
蝰蛇（加法蛇）和响尾蛇制造血液毒素，这种毒素被称为溶血性毒素。
Both poisons are unpleasant, but by far the more unpleasant is the blood poison.
两种毒药都很令人不快，但显然更令人不快的是血液毒素。
It is said that the nerve poison is the more primitive of the two, that the blood poison is, so to speak, a newer product from an improved formula.
据说神经毒素是两者中较原始的一种，而血液毒素可以说是一种来自改进配方的较新产物。
Be that as it may, the nerve poison does its business with man far more quickly than the blood poison.
尽管如此，神经毒素对人类起作用的速度远比血液毒素快得多。
This, however, means nothing.
然而，这什么也意味着。
Snakes did not acquire their poison for use against man but for use against prey such as rats and mice, and the effects on these of viperine poison is almost immediate.
蛇获得毒液并非为了对付人类，而是为了对付老鼠和耗子等猎物，且蝰蛇毒液对这些猎物的影响几乎是即时的。