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They were in cipher! Yes, it looked like cipher. Fancy a man lugging with him a book of that description into this nowhere, and studying it -and making notes-in cipher at that! It was, indeed, an extravagant mystery.

"I had been dimly aware for some time of a worrying noise, and when I lifted my eyes I saw the woodpile was gone, and the manager, aided by all the pilgrims, was shouting at me from the riverside. I slipped the book into my pocket. I assure you to leave off reading was like tearing myself away from the shelter of an old and solid friendship.

"I started the lame engine ahead. 'It must be this miserable trader-this intruder,' exclaimed the manager, looking back malevolently at the place we had left. 'He must be English,' I said. 'It will not save him from getting into trouble if he is not careful,' muttered the manager, darkly. I observed with assumed innocence that no man was safe from trouble in this world.

above. But what-and how much? eyes.
That was the question. We com-
mented adversely upon the imbecility
of that telegraphic style. The bush
around said nothing, and would not let
us look very far, either. A torn cur-
tain of red twill hung in the doorway
of the hut and flapped sadly in our
faces. The dwelling was dismantled;
but we could see a white man had lived
there not very long ago. There re-
mained a rude table-a plank on two
posts; a heap of rubbish reposed in a
dark corner, and by the door I picked
up a book. It had lost its covers, and
the pages had been thumbed into a
state of extremely dirty softness; but
the back had been lovingly stitched
afresh with white cotton thread, which
looked clean yet. It was an extraordi-
nary find. Its title was 'An Inquiry
into Some Points of Seamanship,' by a
man Tower, Towson-some such name
-master in His Majesty's navy. The
matter looked dreary reading enough,
with illustrative diagrams and repul-
sive tables of figures, and the copy was
60 years old. I handled this amazing
antiquity with the greatest possible ten-
derness, lest it should dissolve in my
hands. Within, Towson or Towser was
inquiring earnestly into the breaking
strain of ships' chains and tackle and
other such matters. Not a very en-
thralling book; but at the first glance
you could see there a singleness of in-
tention, an honest concern for the right
way of going to work, which made
these humble pages, though out so
many years ago, luminous with another
than a professional light. The simple
old sailor with his talk of chains and
purchases made one forget the jungle
and the pilgrims in a delicious sensa-
tion of having come upon something
unmistakably real. Such a book being
there was wonderful enough, but still
more astounding were the notes pen-
ciled in the margin and plainly refer-
ring to the text. I couldn't believe my

"The current was more rapid now, the steamer seemed at her last gasp, the stern wheel flopped languidly, and I caught myself listening on tiptoe for the next beat of the float, for, in sober truth, I expected the wretched thing to give up every moment. It was like watching the last flickers of a life. But still we crawled. Sometimes I would pick out a tree a little way ahead to measure our progress towards Kurtz by, but I lost it invariably before we got abreast. To keep the eyes so long on one thing was too much for human patience. The manager displayed a beautiful resignation. I fretted and fumed and took to arguing with myself whether or no I would talk openly with Kurtz; but before I could come to any conclusion it occurred to me that my speech or my silence, indeed any action of mine, would be a mere futility. What did it matter what any one knew or

ignored? What did it matter who was manager? One gets sometimes such a flash of insight. The essentials of this Blackwood's Magazine.

affair lay deep under the surface, beyond my reach and beyond my power of meddling.

(To be continued.)

MIMICRY AND OTHER HABITS OF CRABS.

While standing recently in the vestibule of the South Kensington Natural History Museum, in presence of the statue of Darwin, I noticed a statement on a placard to the effect that in reality our knowledge of the actual habits and life history of animals in a state of naturę is comparatively meagre. This is almost inevitable, since such knowledge can be secured only by observation, which in many cases is necessarily deficient and almost impossible. Particularly is this so in the case of marine life; and even more when the special phase of that life is predominantly submarine. Here observations become exceedingly difficult, and it is only after much patience that nature is made to yield even a scanty portion of her secret.

It may be well to record some new phases I have noted of mimicry and other activities in crabs. For, few though they be, they will help, nevertheless, to swell the mass of facts necessary to the final record of life in the sea, which at present seems such a vast realm of mystery.

The word "mimicry" I shall employ here in its broadest sense. Messrs. Bate and Wallace have used it in connection with butterflies imitating each other. I shall use it of crabs simulating their surroundings. I am not aware that mimicry in any of the higher inhabitants of the sea has been treated by any one before. Some who have glanced at the subject seem to favor the idea that light, acting on the pig

ment cells in the skin, is the involuntary cause of most of the varying colors in these creatures. But I am led to believe that this, in itself, is a slow process, and would take a considerable time to develop changes, whereas all the cuttles and many other forms of sea life can instantly change from one color to another; and I can scarcely see how this can be done, except by the eye, through the nervous system acting on the will.

Hence the question may be asked: How can the crab show these changes, having no skin, and hence no active color sacs, like the cuttles, wherewith to distribute this coloring matter?

To this I remark that the carapace, or shell of the crab, in addition to being the bones and framework of the animal, is also its true skin; a thick, massive armor, certainly, but possessing all necessary conditions of the skin. Hence the hairs growing on various parts of the body, especially near the head, are in touch with the nervous system; and the means for changing color, though much slower, are provided somewhat on the same lines as in the case of the cuttles.

The carapace is mostly composed of carbonate of lime; and the coloring of the shell depends on a pigment which pervades different parts of the substance. This lime and earthy matter is drawn from the sea by an organized membrane, and is at the will of the creature.

My first difficulty with this subject,

In the

after puzzling over the remarks of Pieper, Poulton, Simroth, Cunningham, Newbigin and others, with their negation or approval of protective coloration, natural selection, mimicry and color in nature, has been whether the acts I shall describe in these creatures are voluntary or involuntary. mimetic coloring of the butterflies given by Wallace it would seem that the latter word represents their case. But, in the face of the facts I shall produce, there will appear a doubt whether this idea can be applied to any of these marine creatures.

Hypothetically, this article favors the view that the action of crabs in mimicking their surroundings is voluntary; but the question whether voluntary or involuntary is for future decision, when more abundant facts have been collected.

My first remarks will be on Carcinus mænas, or the common

SHORE CRAB.

It was long thought nat these creatures, at the beginning of autumn, left the shallow and tidal harbors of Devon and Cornwall and went into the deep sea; but it has been discovered that they really do not go far out, but simply burrow under the sands, just outside low water spring tides.2 There they exist through the winter in a semitorpid condition; and while in this state such of the females as have spawn in them transfer their eggs from the internal shell to the underpart of the flap or tail by a beautiful and involuntary process. It would seem that before they leave this sheltered position in May the eggs are cast in the sand, and are alive in about forty-eight hours after being shed.

But this is only one side of their

1 For the names of crabs I shall follow Bell; of cuttles, Gosse; of fishes, Couch; of seaweeds, Grattann.

2 If the sands are not convenient, the crabs will

varied existence; for most of the females which have not spawned in the sands have to pass through the process of exuviation. At a later date, as the summer advances, they retire to the roughest grounds in the neighborhood, generally at extreme low water spring tides; and on the sheltered side, away from the dash of the sea, under the largest stones, they scoop out for themselves homes, where they pass through this difficult and important change. Here in a few days they sometimes double their size and develop from puny maidens into full-grown crabs, when they are followed by the males, whose first act is to enlarge their dwelling, seeing they about one-third larger than the females. To the best of their ability the males here protect the weaker sex from their enemies in passing through this plastic and helpless condition; and, on the partial hardening of the carapace, continue the final act of congress in their domestic retreats.

are

Here, also, in the late summer, may be found females spawning, which were not ready for this act, in the sands, during the spring. How far into the autumn spawning is continued it is difficult to decide, on account of the tides, but young crabs, in their first forms, may be found on the coasts from June to January.

Up to this point I have only been describing the shore crabs on the open coasts; but in our natural deep-water harbors, such as Plymouth and Fowey, where they are sheltered from the winter storms which beat upon the shore, their practice varies very much from that of those which live outside. There they never take up the hybernating habit and have a winter's rest like their congeners in the open sea, but are

be found near in the most sheltered position where stones are plentiful, just outside low water spring tides.

forever in waking hours on the alert, and only use the sands or mud for rest, protection and the final acts of procreation.

Let us consider again their general habits in the open sea. Beside being scavengers of the shore, they prey upon every living organism near them; and as they can see just as well out of water as in it, they will sometimes crawl short distances out of the sea to secure some dainty food; and on sea beaches, when hunger presses them hard, they will even come above the waves at high water and hunt after the sand-hoppers there.

These anxious business habits are very attractive to the children of the coasts, who often receive their first fishing lessons in the capture of these little sinners,3 with thread and pin hook. It is said that rats fish for them in the same way, using their own tails as lines and bait. Of this, I think, there can be no doubt, the great huntingground of the rats throughout the summer and autumn being the coast-line of the sea, and their quarry chiefly these crabs. Mevagissey old pier was built without lime, and it is not uncommon to see rats, between high and low water, hunting through this structure for these invertebrata. On one occasion I saw a rat with its hinder parts sodden with water, while the tip of its tail was quite white, as if it had just been used as a bait.

These shore crabs, although less than three ounces in weight and their carapace seldom stretching to three inches, when cornered in difficulties will face any enemy, however large. Possibly these fighting proclivities may have been intensified by the fact that from the first dawn of existence they have never had any kind of maternal or parental assistance, having had to fight the battle of life alone. The grip of their

3 On many parts of the coast they are called by this name.

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them hold on to the lifting of over eighty times their own weight.

But notwithstanding this strength and courage, they know well the difficulty there is in living near the shore, with the sea-birds, man and an army of rats as their inveterate enemies. Moreover, in the great light of our shallow seas, their chief trouble is in getting any kind of living food. Hence the whole race, with more than human tenacity, cling to mimicry as the sheetanchor of life; and when many of its varied forms of deception fail, they have no hesitation in simulating death, as will be seen as I proceed. On the coasts of Cornwall, near Mevagissey, the powdered white sea-shells mixed with the broken mica-schist rocks give us a brown sand. These are often interspersed with white markings from quartz pebbles; hence the first act of many young crabs here in the spring is to color their carapace brown with white spots.

On Portmelon beach, where the brown sands and the white shingle mix freely together, I have seen crabs up to an inch and a half across the back with these white markings prominent, whereas the same sized crabs in Mevagissey pier on the black mud assume a dark green, approaching an almost pitchy hue; while on the open coasts in the summer months, between high and ordinary low water, the principal color is green, because of the preponderance of green sea-weeds there. This, however, is modified into light and dark hues by the presence of dark mud and stones or light sands and shells. In all these shades the crabs imitate their environments, even to giving the white patch on their carapace a greenish tinge, especially in the pools, where it either hides them from their enemies or gives them better opportunities of pouncing on living food; whereas at extreme low water, in their chosen retreats un

der the stones, where coral and worm life give a red hue to their surroundings, the males and some females dress the whole of their exposed parts in a red color, and even the brown back, which is mostly hidden, has a red tinge.

Their feigning death is often seen after a fight or a struggle for life in which they have been badly worsted. This often happens when, after being caught in a shore seine, all their efforts to escape have failed, and they are drawn in on the beach. Then their simulation of the end is almost perfect. This is also seen when they are fighting with the human hand and are overcome. Then the assumption of death is their final act; sometimes it takes the form of rigidity of limbs, as if they were dying in a fit, and at other times a rag-like limpness as if life were gone. To show that these creatures have an innate desire for this kind of trickery, let me describe half an hour in the life of one of them.

Some time ago I was waiting for the tide to come into a neighboring harbor, and with its advances I noticed that quantities of young prawns were anxious to explore its mud and sea-weed, and that in the long furrow made by the last ship's keel, these active creatures came along by the score. Many had not passed in before Carcinus mœnas came to the front, out of the mud. At once he showed me he had a design on the life of these prawns, for he quietly crept into the keel-mark and stood across their track with extended claws and open nippers; and in his green-gray form, covered with dirt and mud, he could scarcely be seen on the sea bottom. Here he waited to grapple with the first comer. But wariness barely expresses the watchful care of these prawns, for the crab was noted

Professor Milne Edwards regards the inner pair of antennae, in crabs generally, as organs of smell, and the outer and longer pair as organs of hearing. As prawns have three pairs of an

at once, and they came up to him with extended antennæ, and either touched or smelt his nippers, and quickly passed by on the other side. This was done again and again, but he stood like a statue under their scrutiny. At last one of the prawns seemed to come a little nearer than the others, and the final rush and nip were given, but without effect, for the feelers were quickly withdrawn, and with a flip of the tail the creature was out of reach.

But although unsuccessful, the crab was not without further resources. His next move was to look around the track a little, and soon he found some green sea-weeds near. These he touched up lightly, and after moving them a little more to the centre, he quietly got into the middle of them, and again stood up with extended claws and open nippers. Here the green crab, in these green garments, was fairly hidden.

Quickly but cautiously again came on the prawns. Soon their antennæ struck his open nippers in the weeds, and again in cautious haste they moved

away.

Patience is said to be a virtue, and if it is so, this little crab had a good share of it, for more than a score of these prawns touched his nippers in the weeds, and went their way without coming within gripping distance of the silent watcher.

At last his virtuous feelings became exhausted, and he rushed with violence on his wary neighbors, but without effect, for, with a swift move of their tails, they were out of danger. But the crab's artifice was not yet ended. After taking a little rest (for now his arms must have been as weary as those of the disobedient schoolboy after the punishment of holding out his book) he began to search for a soft place on

tennae, we are led to believe from the actions of these creatures that the third and longer pair are organs of feeling, and, to some extent, answer the purpose of the human hand.

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