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Average One Directory 20
Page 06
On October 25th we went down first the Limao rapid, and then the Burbure rapid. The river was beautiful all along, with low hills on both sides. We eventually arrived at Pimental, a fiendishly hot, steamy, unhealthy place, where across a streamlet was a station for the transhipment of rubber. The place was on low ground, which became inundated at high water. Another station was built some 200 m. off on high ground, which was used as a winter station. The second station was at the beginning of an excellent mule track which Col. Brazil had cut as far as a place lower down the river called Bella Vista, a distance of some 20 kil. He had imported at much expense a number of mules for the service. All the rubber was conveyed from that spot on mule-back, as between Pimental and Bella Vista was a dangerous rapid, on which many boats had been lost.
Among the dozen or more butterflies and moths which winter in the perfect state, the most common and the most handsome is the "Camberwell beauty" or "mourning cloak," _Vanessa antiopa_ L., a large butterfly whose wings are a rich purplish brown above, duller beneath, and broadly margined with a yellowish band. It is often found in winter beneath chunks which are raised a short distance above the ground, or in the crevices of old snags and fence rails. It is then apparently lifeless, with the antennae resting close along the back, above which the wings are folded. But one or two warm days are necessary to restore it to activity, and I have seen it on the wing as early as the 2d of March, hovering over the open flowers of the little snow trillium.
Without taking into account insects and such other "small deer,"--to quote Shakespeare's expression,--this fundamental principle of population will become at once apparent if we examine merely familiar instances of back-boned or vertebrate animals. The lowest vertebrates are clearly the fishes: and the true fishes have almost invariably gigantic families. A single cod, for example, is said to produce, roughly speaking, nine million eggs at a birth (I cannot pretend I have checked this calculation); but supposing they were only a million, and that one-tenth of those eggs alone ever came to maturity, there would still be a hundred thousand codfish in the sea this year for every pair that swam in it last year: and these would increase to a hundred thousand times that number next year; and so on, till in four or five years' time the whole sea would be but one solid mass of closely-packed cod-banks. We can see for ourselves that nothing of the sort actually occurs--practically speaking, there are about the same number of cod one year as another. In spite of this enormous birth-rate, therefore, the cod population is not increasing--it is at a standstill. What does that imply? Why, that taking one brood and one year with another, only a pair of cod, roughly speaking, survive to maturity out of each eight or nine million eggs. The mother cod lays its millions, in order that two may arrive at the period of spawning. All the rest get devoured as eggs, or snapped up as young fry, or else die of starvation, or are otherwise unaccounted for. It seems to us a wasteful way of replenishing the earth: but it is nature's way; we can only bow respectfully to her final decision.
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