The ice we had taken aboard at La Paz was all gone now. We started our little motor and ran it for hours to cool the ice-chest, but the heat on deck would not permit it to drop the temperature below about thirty-eight degrees F., and the little motor struggled and died often, apparently hating to run in such heat. It sounded tired and sweaty and disgusted. When the evening came, we had fried fish, caught that day, and after dark we lighted the deck and put our reflecting lamp over the side. We netted a serpent-like eel, thinking from its slow, writhing movement through the water that it might be one of the true viperine sea-snakes which are common farther south. Also we captured some flying fish.
We used long-handled dip-nets in the lighted water, and set up the enameled pans so that the small pelagic animals could be dropped directly into them. The groups in the pans grew rapidly. There were
heteronereis
(the free stages of otherwise crawling worms who develop paddle-like tails upon sexual maturity). There were swimming crabs, other free-swimming annelids, and ribbon-fish which could not be seen at all, so perfectly transparent were they. We should not have known they were there, if they had not thrown faint shadows on the bottom of the pans. Placed in alcohol, they lost their transparency and could easily be seen. The pans became crowded with little skittering animals, for each net brought in many species. When the hooded light was put down very near the water, the smallest animals came to it and scurried about in a dizzying dance so rapidly that they seemed to draw crazy lines in the water. Then the small fishes began to dart in and out, snapping up this concentration, and farther out in the shadows the large wise fishes cruised, occasionally swooping and gobbling the small fishes. Several more of the cream-colored spotted snake-eels wriggled near and were netted. They were very snake-like and they had small bright-blue eyes. They did not swim with a beating tail as fishes do, but rather squirmed through the water.
While we worked on the deck, we put down crab-nets on the bottom, baiting them with heads and entrails of the fish we had had for dinner. When we pulled them up they were loaded with large stalk-eyed snails
56
and with sea-urchins having long vicious spines.
57
The colder-water relatives of both these animals are very slow-moving, but these moved quickly and were completely voracious. A net left down five minutes was brought up with at least twenty urchins in it, and all attacking the bait. In addition to the speed with which they move, these urchins are clever and sensitive with their spines. When approached, the long sharp little spears all move and aim their points at the approaching body until the animal is armed like a Macedonian phalanx. The main shafts of the spines were cream-yellowish-white, but a half-inch from the needle-points they were blue-black. The prick of one of the points burned like a bee-sting. They seemed to live in great numbers at four fathoms; we do not know their depth range, but their physical abilities and their voraciousness would indicate a rather wide one. In the same nets we took several dromiaceous crabs, reminiscent of hermits, which had adjusted themselves to life in half the shell of a bivalve, and had changed their body shapes accordingly.
It is probable that no animal tissue ever decays in this water. The furious appetites which abound would make it unlikely that a dead animal, or even a hurt animal, should last more than a few moments. There would be quick death for the quick animal which became slow, for the shelled animal which opened at the wrong time, for the fierce animal which grew timid. It would seem that the penalty for a mistake or an error would be instant death and there would be no second chance.
It would have been good to keep some of the sensitive urchins alive and watch their method of getting about and their method of attack. Indeed, we will never go again without a full-sized observation aquarium into which we can put interesting animals and keep them for some time. The aquaria taken were made with polarized glass. Thus, the fish could look out but we could not look in. This, it turned out, was an error on our part.
There are three ways of seeing animals: dead and preserved; in their own habitats for the short time of a low tide; and for long periods in an aquarium. The ideal is all three. It is only after long observation that one comes to know the animal at all. In his natural place one can see the normal life, but in an aquarium it is possible to create abnormal conditions and to note the animal’s adaptability or lack of it. As an example of this third method of observation, we can use a few notes made during observation of a small colony of anemones in an aquarium. We had them for a number of months.
In their natural place in the tide pool they are thick and close to the rock. When the tide covers them they extend their beautiful tentacles and with their nettle-cells capture and eat many microorganisms. When a powerful animal, a small crab for example, touches them, they paralyze it and fold it into the stomach, beginning the digestive process before the animal is dead, and in time ejecting the shell and other indigestible matter. On being touched by an enemy, they fold in upon themselves for protection. We brought a group of these on their own stone into the laboratory and placed them in an aquarium. Cooled and oxygenated sea water was sprayed into the aquarium to keep them alive. Then we gave them various kinds of food, and found that they do not respond to simple touch-stimulus on the tentacles, but have something which is at least a vague parallel to taste-buds, whatever may be the chemical or mechanical method. Thus, protein food was seized by the tentacles, taken and eaten without hesitation; fat was touched gingerly, taken without enthusiasm to the stomach, and immediately rejected; starches were not taken at all—the tentacles touched starchy food and then ignored it. Sugars, if concentrated, seemed actually to burn them so that the tentacles moved away from contact. There did really appear to be a chemical method of differentiation and choice. We circulated the same sea water again and again, only cooling and freshening it. Pure oxygen, introduced into the stomach in bubbles, caused something like drunkenness; the animal relaxed and its reaction to touch was greatly slowed, and sometimes completely stopped for a while. But the reaction to chemical stimulus remained active, although slower. In time, all the microscopic food was removed from the water through constant circulation past the anemones, and then the animals began to change their shapes. Their bodies, which had been thick and fat, grew long and neck-like; from a normal inch in length, they changed to three inches long and very slender. We suspected this was due to starvation. Then one day, after three months, we dropped a small crab into the aquarium. The anemones, moving on their new long necks, bent over and attacked the crab, striking downward like slow snakes. Their normal reaction would have been to close up and draw in their tentacles, but these animals had changed their pattern in hunger, and now we found that when touched on the body, even down near the base, they moved downward, curving on their stalks, while their tentacles hungrily searched for food. There seemed even to be competition among the individuals, a thing we have never seen in a tide pool among anemones. This versatility had never been observed by us and is not mentioned in any of the literature we have seen.
The aquarium is a very valuable extension of shore observation. Quick-eyed, timid animals soon become used to having humans about, and quite soon conduct their business under lights. If we could have put our sensitive urchins in an aquarium, we could have seen how it is that they move so rapidly and how they are stimulated to aim their points at an approaching body. But we preserved them, and of course they lost color and dropped many of their beautiful sharp spines. Also, we could have seen how the great snails are able to consume animal tissue so quickly. As it is, we do not know these things.
19
MARCH 29
Tides had been giving us trouble, for we were now far enough up the Gulf so that the tidal run had to be taken into time consideration. In the evening we had set up a flagged stake at the waterline, so that with glasses we could see from the deck the rise and fall of the tide in relation to the stick. At seven-thirty in the morning the tide was going down from our marker. We had abandoned our tide charts as useless by now, and since we stayed such a short time at each station we could not make new ones. The irregular length of our jumps made it impossible for us to forecast with accuracy from a preceding station. Besides all this, a good, leisurely state of mind had come over us which had nothing to do with the speed and duration of our work. It is very possible to work hard and fast in a leisurely manner, or to work slowly and clumsily with great nervousness.
On this day, the sun glowing on the morning beach made us feel good. It reminded us of Charles Darwin, who arrived late at night on the
Beagle
in the Bay of Valparaiso. In the morning he awakened and looked ashore and he felt so well that he wrote, “When morning came everything appeared delightful. After Tierra del Fuego, the climate felt quite delicious, the atmosphere so dry and the heavens so clear and blue with the sun shining brightly, that all nature seemed sparkling with life.”
58
Darwin was not saying how it was with Valparaiso, but rather how it was with him. Being a naturalist, he said, “All nature seemed sparkling with life,” but actually it was he who was sparkling. He felt so very fine that he can, in these charged though general adjectives, translate his ecstasy over a hundred years to us. And we can feel how he stretched his muscles in the morning air and perhaps took off his hat—we hope a bowler—and tossed it and caught it.
On this morning, we felt the same way at Concepción Bay. “Everything appeared delightful.” The tiny waves slid up and down the beach, hardly breaking at all; out in the Bay the pelicans were fishing, flying along and then folding their wings and falling in their clumsy-appearing dives, which nevertheless must be effective, else there would be no more pelicans.
By nine A.M. the water was well down, and by ten seemed to have passed low and to be flowing again. We went ashore and followed the tide down. The beach is steep for a short distance, and then levels out to a gradual slope. We took two species of cake urchins which commingled at one-half to one and one-half feet of water at low tide. The ordinary cake urchin here, with holes, is
Encope californica
Verrill. The grotesquely beautiful keyhole sand dollar
59
was very common here. Finally, there was a rare member of the same group,
60
which we collected unknowingly, and turned out only three individuals of the species when the animals were separated on deck. A little deeper, about two feet submerged, at low tide, a species of cucumber new to us was taken, a flat, sand-encrusted fellow.
61
Giant heart-urchins
62
in some places were available in the thousands. They ranged between two feet and three feet below the surface at low water, and very few were deeper. The greatest number occurred at three feet.
The shore line here is much like that at Puget Sound: in the high littoral is a foreshore of gravel to pebbles to small rocks; in the low littoral, gravelly sand and fine sand with occasional stones below the low tide level. In this zone, with a maximum at four feet, were heavy groves of algae, presumably
Sargassum,
lush and tall, extending to the surface. Except for the lack of eel-grass, it might have been Puget Sound. We took giant stalk-eyed conchs,
63
several species of holothurians and Cerianthus, the sand anemone whose head is beautiful but whose encased body is very ugly, like rotting gray cloth. Tiny christened
Cerianthus
“sloppy-guts,” and the name stuck. By diving, we took a number of hachas, the huge mussel-like clams. Their shells were encrusted with sponges and tunicates under which small crabs and snapping shrimps hid themselves. Large scalloped limpets also were attached to the shells of the hachas. This creature closes itself so tightly with its big adductor muscle that a knife cannot penetrate it and the shell will break before the muscle will relax. The best method for opening them is to place them in a bucket of water and, when they open a little, to introduce a sharp, thin-bladed knife and sever the muscle quickly. A finger caught between the closing shells would probably be injured. In many of the hachas we found large, pale, commensal shrimps
64
living in the folds of the body. They are soft-bodied and apparently live there always.
About noon we got under way for San Lucas Cove, and as usual did our preserving and labeling while the boat was moving. Some of the sand dollars we killed in formalin and then set in the sun to dry, and many more we preserved in formaldehyde solution in a small barrel. We had taken a great many of them. Sparky had, by now, filled several sacks with the fine white rose-lined murex shells, explaining, as though he were asked for an explanation, that they would be nice for lining a garden path. In reality, he simply loved them and wanted to have them about.
We passed Mulege, that malaria-ridden town, that town of high port fees—so far as we know—and it looked gay against the mountains, red-roofed and white-walled. We wished we were going ashore there, but the wall of our own resolve kept us out, for we had said, “We will not stop at Mulege,” and having said it, we could not overcome our own decision. Sparky and Tiny looked longingly at it as we passed; they had come to like the quick excursions into little towns: they found that their Italian was understood for any purposes they had in mind. It was their practice to wander through the streets, carrying their cameras, and in a very short time they had friends. Tony and Tex were foreigners, but Tiny and Sparky were very much at home in the little towns—and they never inquired whose home. This was not reticence, but rather a native tactfulness.