Surrounding the cleared portions around Greytown is a scrubby bush, amongst which are many guayava trees (Psidium sp.) having a fruit like a small apple filled with seeds, of a sub-acid flavour, from which the celebrated guava jelly is made. The fruit itself often occasions severe fits of indigestion, and many of the natives will not swallow the small seeds, but only the pulpy portion, which is said to be harmless. I saw another fruit growing here, a yellow berry about the size of a cherry, called "Nancito" by the natives. It is often preserved by them with spirit and eaten like olives. Beyond the brushwood, which grows where the original forest has been cut down, there are large trees covered with numerous epiphytes—Tillandsias, orchids, ferns, and a hundred others, that make every big tree an aerial garden. Great arums perch on the forks and send down roots like cords to the ground, whilst lianas run from tree to tree or hang in loops and folds like the disordered tackle of a ship.
Green parrots fly over in screaming flocks, or nestle in loving couples amidst the foliage, toucans hop along the branches, turning their long, highly-coloured beaks from side to side with an old-fashioned look, and beautiful tanagers (Ramphocaelus passerinii) frequent the outskirts of the forest, all velvety black, excepting a large patch of fiery-red above the tail, which renders the bird very conspicuous. It is only the male that is thus coloured, the female being clothed in a sober suit of greenish-brown. I think this bird is polygamous, for several of the brown ones were always seen with one of the red-and-black ones. The bright colours of the male must make it very conspicuous to birds of prey, and, probably in consequence, it is not nearly so bold as the obscurely-coloured females. When a clear space in the brushwood is to be crossed, such as a road, two or three of the females will fly across first, before the male will venture to do so, and he is always more careful to get himself concealed amongst the foliage than his mates.
I walked some distance into the forest along swampy paths cut by charcoal burners, and saw many beautiful and curious insects. Amongst the numerous butterflies, large blue Morphos and narrow, weak-winged Heliconidae, striped and spotted with yellow, red, and black, were the most conspicuous and most characteristic of tropical America. Amongst the beetles I found a curious longicorn (Desmiphora fasciculata), covered with long brown and black hairs, and closely resembling some of the short, thick, hairy caterpillars that are common on the bushes. Other closely allied species hide under fallen branches and logs, but this one clung exposed amongst the leaves, its antennae concealed against its body, and its resemblance to a caterpillar so great, that I was at first deceived by it. It is well known that insectivorous birds will not touch a hairy caterpillar, and this is only one of numberless instances where insects, that have some special protection against their enemies, are closely imitated by others belonging to different genera, and even different orders. Thus, wasps and stinging ants have hosts of imitators amongst moths, beetles, and bugs, and I shall have many curious facts to relate concerning these mimetic resemblances. To those not acquainted with Mr. Bates's admirable remarks on mimetic forms, I must explain that we have to speak of one species imitating another, as if it were a conscious act, only on account of the poverty of our language. No such idea is entertained, and it would have been well if some new term had been adopted to express what is meant. These deceptive resemblances are supposed, by the advocates of the origin of species by natural selection, to have been brought about by varieties of one species somewhat resembling another having special means of protection, and preserved from their enemies in consequence of that unconscious imitation. The resemblance, which was perhaps at first only remote, is supposed to have been increased in the course of ages by the varieties being protected that more and more closely approached the species imitated, in form, colour, and movements. These resemblances are not only between insects of different genera and orders, but between insects and flowers, leaves, twigs, and bark of trees, and between insects and inanimate nature. They serve often for concealment, as when leaves are imitated by leaf-insects and many butterflies, or for a disguise that enables predatory species to get within reach of their prey, as in those spiders that resemble the petals of flowers amongst which they hide.
(PLATE 1. ALLIGATORS IN SAN JUAN RIVER.)
That I may not travel over the same ground twice, I may here mention that on a subsequent visit to Greytown I rode a few miles northward along the beach. On my return, I tied up the horse and walked about a mile over the sand-bank that extends down to the mouth of the river. A long, deep branch forms a favourite resort for alligators. At the far end of a sand-spit, near where some low trees grew, I saw several dark objects lying close to the water on the shelving banks. They were alligators basking in the sun. As I approached, most of them crawled into the water. Mr. Hollenbeck had been down a few days before shooting at them with a rifle, to try to get a skull of one of the monsters, and I passed a dead one that he had shot. As I walked up the beach, I saw many that were not less than fifteen feet in length. One lay motionless, and thinking it was another dead one, I was walking up to it, and had got within three yards, when I saw the film over its eye moving; otherwise it was quite still, and its teeth projecting beyond its lips added to its intense ugliness and appearance of death. There was no doubt, however, about the movement of the eye-covers, and I went back a short distance to look for a stick to throw at it; but when I turned again, the creature was just disappearing into the water. It is their habit to lie quite still, and catch animals that come near them. Whether or not it was waiting until I came within the swoop of its mighty tail I know not, but I had the feeling that I had escaped a great danger. It was curious that it should have been so bold only a few days after Mr. Hollenbeck had been down shooting at them. There were not less than twenty altogether, and they swam out into the middle of the inlet and floated about, looking like logs in the water, excepting that one stretched up its head and gave a bellow like a bull. They sometimes kill calves and young horses, and I was told of one that had seized a full-grown horse, but its struggles being observed, some natives ran down and saved it from being pulled into the water and drowned. I heard several stories of people being killed by them, but only one was well authenticated. This was told me by the head of the excellent Moravian Mission at Blewfields, who was a witness of the occurrence. He said that one Sunday, after service at their chapel at Blewfields, several of the youths went to bathe in the river, which was rather muddy at the time; the first to plunge in was a boy of twelve years of age, and he was immediately seized by a large alligator, and carried along under water. My informant and others followed in a canoe, and ultimately recovered the body, but life was extinct. The alligator cannot devour its prey beneath the water, but crawls on land with it after he has drowned it. They are said to catch wild pigs in the forest near the river by half burying themselves in the ground. The pigs come rooting amongst the soil, the alligator never moves until one gets within its reach, when it seizes it and hurries off to the river with it. They are often seen in hot weather on logs or sand-spits lying with their mouths wide open. The natives say they are catching flies, that numbers are attracted by the saliva of the mouth, and that when sufficient are collected, the alligator closes its jaws upon them, but I do not know that any reliance can be placed on the story. Probably it is an invention to account for the animals lying with their mouths open; as in all half-civilised countries I have visited I have found the natives seldom admit they do not know the reason of anything, but will invent an explanation rather than acknowledge their ignorance.
CHAPTER 2.
Commence journey up San Juan river.
Palms and wild canes.
Plantations.
The Colorado river.
Proposed improvement of the river.
Progress of the delta.
Mosquitoes.
Disagreeable night.
Fine morning.
Vegetation of the banks.
Seripiqui river.
Mot-mots.
Foraging ants: their method of hunting.
Ant-thrushes.
They attack the nests of other ants.
Birds' nests, how preserved from them.
Reasoning powers in ants.
Parallel between the Mammalia and the Hymenoptera.
Utopia.
I FOUND at Greytown the mail-boat of the Chontales Gold-Mining Company, which came down monthly in charge of Captain Anderson, an Englishman who had knocked about all over the world. The crew consisted of four Mosquito negroes, who are celebrated on this coast for their skill as boatmen. Besides the crew, we were taking three other negroes up to the mines, and with my boxes we were rather uncomfortably crowded for a long journey. The canoe itself was made from the trunk of a cedar-tree (Cedrela odorata). It had been hollowed out of a single log, and the sides afterwards built up higher with planking. This makes a very strong boat, the strength and thickness being where it is most required, at the bottom, to withstand the thumping about amongst the rocks of the rapids. I was once in one, coming down a dangerous rapid on the river Gurupy, in Northern Brazil, when we were driven with the full force of the boiling stream broadside upon a rock, with such force that we were nearly all thrown down, but the strong canoe was uninjured, although no common boat could have withstood the shock.
Having determined to go up the river in this boat, we took provisions with us for the voyage, and one of the negroes agreed to act as cook. Having arranged everything, and breakfasted with my kind friends, Mr. and Mrs. Hollenbeck, I bade them adieu, and settled myself into the small space in the canoe that I expected to occupy for six days. Captain Anderson took the helm, the "Caribs" dipped their paddles into the water, and away we glided into a narrow channel amongst long grass and rushes that almost touched us on either side. Greytown, with its neat white houses, and feathery palms, and large-leaved bread-fruit trees, was soon shut from our view, and our boatmen plying their paddles with the greatest dexterity and force, made the canoe shoot along through the still water. Soon we emerged into a wider channel where a stronger stream was running, and then we coasted along close to the shore to avoid the strength of the current. The banks at first were low and marshy and intersected by numerous channels; the principal tree was a long, coarse-leaved palm, and there were great beds of wild cane and grass, amongst which we occasionally saw curious green lizards, with leaf-like expansions (like those on the leaf-insects), assimilating them in appearance to the vegetation amongst which they sought their prey. As we proceeded up the river, the banks gradually became higher and drier, and we passed some small plantations of bananas and plantains made in clearings in the forest, which now consisted of a great variety of dicotyledonous trees with many tall, graceful palms; the undergrowth being ferns, small palms, Melastomae, Heliconiae, etc. The houses at the plantations were mostly miserable thatched huts with scarcely any furniture, the owners passing their time swinging in dirty hammocks, and occasionally taking down a canoe-load of plantains to Greytown for sale. It is one of the rarest sights to see any of these squatters at work. Their plantain patch and occasionally some fish from the river suffice to keep them alive and indolent.
At seven o'clock we reached the Colorado branch, which carries off the greater part of the waters of the San Juan to the sea. This is about twenty miles above Greytown, but only eighteen by the Colorado to the sea, and is near the head of the delta, as I have already mentioned. The main body of water formerly flowed down past Greytown, and kept the harbour there open, but a few years ago, during a heavy flood, the river greatly enlarged and deepened the entrance to the Colorado Channel, and since then year by year the Greytown harbour has been silting up. Now (I am writing in 1873) there is twelve feet of water on the bar at the Colorado in the height of the dry season, whilst at Greytown the outlet of the river is sometimes closed altogether. The merchants at Greytown have entertained the project of dredging out the channel again, but now that the river has found a nearer way to the sea by the Colorado this would be a herculean task, and it would cost much less money to move the whole town to the Colorado, where by dredging the bar a fine harbour might easily be made, but unfortunately the Colorado is in Costa Rica, the Greytown branch in Nicaragua, and there are constant bickerings between the two states respecting the outlet of this fine river, which make any well-considered scheme for the improvement of it impracticable at present. A sensible solution of the difficulty would be a federation of the two small republics. The heads of the political parties in the two countries see, however, in this a danger to their petty ambitions, and will not risk the step, and so the boundary question remains an open one, threatening at any moment to plunge the two countries into an impoverishing war.