Inhabitants Of My Pool

(From Magic Glasses.)

By

ARABELLA B. BUCKLEY.

The pool lies in a deep hollow among a group of rocks and boulders, close to the entrance of the cove, which can only be entered at low water; it does not measure more than two feet across, so that you can step over it, if you take care not to slip on the masses of green and brown seaweed growing over the rocks on its sides, as I have done many a time when collecting specimens for our salt-water aquarium. I find now the only way is to lie flat down on the rock, so that my hands and eyes are free to observe and handle, and then, bringing my eye down to the edge of the pool, to lift the seaweeds and let the sunlight enter into the chinks and crannies. In this way I can catch sight of many a small being either on the seaweed or the rocky ledges, and even creatures transparent as glass become visible by the thin outline gleaming in the sunlight. Then I pluck a piece of seaweed, or chip off a fragment of rock with a sharp-edged collecting knife, bringing away the specimen uninjured upon it, and place it carefully in its own separate bottle to be carried home alive and well.

Now though this little pool and I are old friends, I [pg 367] find new treasures in it almost every time I go, for it is almost as full of living things as the heavens are of stars, and the tide as it comes and goes brings many a mother there to find a safe home for her little ones, and many a waif and stray to seek shelter from the troublous life of the open ocean.

You will perhaps find it difficult to believe that in this rock-bound basin there can be millions of living creatures hidden away among the fine feathery weeds; yet so it is. Not that they are always the same. At one time it may be the home of myriads of infant crabs, not an eighth of an inch long, another of baby sea-urchins only visible to the naked eye as minute spots in the water, at another of young jelly-fish growing on their tiny stalks, and splitting off one by one as transparent bells to float away with the rising tide. Or it may be that the whelk has chosen this quiet nook to deposit her leathery eggs; or young barnacles, periwinkles, and limpets are growing up among the green and brown tangles, while the far-sailing velella and the stay-at-home sea-squirts, together with a variety of other sea-animals, find a nursery and shelter in their youth in this quiet harbor of rest.

And besides these casual visitors there are numberless creatures which have lived and multiplied there, ever since I first visited the pool. Tender red, olive-colored, and green seaweeds, stony corallines, and acorn-barnacles lining the floor, sea-anemones clinging to the sides, sponges tiny and many-colored hiding under the ledges, and limpets and mussels wedged in the cracks. These can be easily seen with the naked eye, but they are not the most numerous inhabitants; for these [pg 368] we must search with a magnifying glass, which will reveal to us wonderful fairy-forms, delicate crystal vases with tiny creatures in them whose transparent lashes make whirlpools in the water, living crystal bells so tiny that whole branches of them look only like a fringe of hair, jelly globes rising and falling in the water, patches of living jelly clinging to the rocky sides of the pool, and a hundred other forms, some so minute that you must examine the fine sand in which they lie under a powerful microscope before you can even guess that they are there.

FIG. 1. GROUP OF SEAWEEDS.
(Natural size.)
1, Ulva Linza. 2, Sphacelaria filicina. 3, Polysiphonia urceolata. 4, Corallina officinalis.

So it has proved a rich hunting-ground, where summer and winter, spring and autumn, I find some form to put under my magic glass. There I can watch it for weeks growing and multiplying under my care; moved only from the aquarium, where I keep it supplied with healthy sea-water, to the tiny [pg 369] transparent trough in which I place it for a few hours to see the changes it has undergone. I could tell you endless tales of transformations in these tiny lives, but I want to-day to show you a few of my friends, most of which I brought yesterday fresh from the pool, and have prepared for you to examine.

FIG. 2. Ulva lactuca, A GREEN-SEAWEED, GREATLY MAGNIFIED TO SHOW STRUCTURE. (After Orested).

s, Spores in the cells, ss, Spores swimming out. h, Holes through which spores have escaped.

Let us begin with seaweeds. I have said that there are three leading colors in my pool—green, olive, and red—and these tints mark roughly three kinds of weed, though they occur in an endless variety of shapes. Here is a piece of the beautiful pale green seaweed, called the Laver or Sea-Lettuce, Ulva Linza (1, Fig. 1), [Note: The slice given in Fig. 2 is from a broader-leaved form, U. lactuca, because this species, being composed of only one layer of cells, is better seen. Ulva Linza is composed of two layers of cells.] which grows in long ribbons in a sunny nook in the water. I have placed under the first microscope a piece of this weed which is just sending out young seaweeds in the shape of tiny cells, with lashes very like those we saw coming from the moss-flower, and I have pressed them in the position in which they would naturally leave the plant. You will also see on this side several cells in which these tiny spores are forming, ready to burst out and swim; for this green weed is merely a collection of cells, like the single-celled plants on land. Each cell [pg 370] can work as a separate plant; it feeds, grows, and can send out its own young spores.

This deep olive-green feathery weed (2, Fig. 1), of which a piece is magnified under the next microscope (2, Fig. 3), is very different. It is a higher plant, and works harder for its living, using the darker rays of sunlight which penetrate into shady parts of the pool. So it comes to pass that its cells divide the work. Those of the feathery threads make the food, while others, growing on short stalks on the shafts of the feather, make and send out the young spores.

Lastly, the lovely red threadlike weeds, such as this Polysiphonia urceolata (3, Fig. 1), carry actual urns on their stems like those of mosses. In fact, the history of these urns (see 3, Fig. 3), is much the same in the two classes of plants, only that instead of the urn being pushed up on a thin stalk as in the moss, it remains on the seaweed close down to the stem, when it grows out of the plant-egg, and the tiny plant is shut in till the spores are ready to swim out.

FIG. 3. THREE SEAWEEDS OF FIG. 1 MUCH MAGNIFIED TO SHOW FRUITS. (Harvey.)

2, Sphacelaria filicina. 3, Polysiphonia urceolata. 4, Corallina officinalis.

Contents