petrel the left side. The former sits with its head close to the entrance so as to defend it, and if a hand or a stick be inserted into the passage, the creature bites at it furiously. The tuatara feeds partly on worms and beetles, and partly on the rem cause death had not ended our existence, | sides of the chamber, the lizard almost count upon "the law of progress" to se- invariably choosing the right, and the cure us a great future in the spiritual life. Apart from faith in God, immortal life should be the most fearful of terrors to us all, should be what Shelley makes Beatrice Cenci conceive as "the wide, grey, lampless, deep, unpeopled world," in which we might meet with any destiny however | nants of fishes and crustaceans brought fearful, because a destiny controlled to their common table by the petrel; both neither by wisdom nor love. It is awful animals being thus benefited by the coenough to think of seventy years without partnery. So much probably cannot be God; but to think of eternity passed not said of the prairie dog, whose underonly without God, but subject to the ground home on the plains of North caprice of laws of the origin and end of America is frequently shared by the ratwhich you know nothing, except that they tlesnake and the burrowing owl. These will yield you, in all probability, no escape were at one time supposed to form a from your conscious existence, no such "happy family," but considerable doubt possibility, even as death, is a conception has been cast on the point by the discov of too grotesque a horror to be perma- ery of young prairie dogs in the stomach nently consistent with the reason of man- of the rattlesnake. In certain parts of kind. To us, at leact, it suggests a spirit- South America the rabbit-like viscacha ual Bedlam or Earlswood, from which has a messmate in a little burrowing owl, there could be no release, since the steady which is thus saved the labor of excavatexpectation of an endless existence to being a home for itself; but in Banda Orilived under the absolute despotism of a soulless, purposeless, and enigmatic fate, would inevitably drive all beings whose minds could by any possibility be unhinged to either insanity or idiocy; or, if that be impossible, in spiritual existence, then to chill, grey, hopeless melancholy. From The English Mechanic. ental, where the viscacha does not occur, the owl has to do its own burrowing. Among insects a few cases of commensalism are on record; but the first known instance of its occurrence among caterpillars was recently recorded by Fritz Müller. He found two caterpillars in Brazil living on the leaves of the mulberry. The larger one was protected by a covering of long, stinging hairs or thorns; and like most caterpillars similarly protected, its coloring was exceedingly bright and conspicuous. The other - a small blackish form- sat across the back of its gaudy partner, enjoying the protection afforded to both by the surrounding stinging hairs. On removing the smaller caterpillar from its retreat, Mr. Müller found that it made its way back again as quickly as it could. Under an anesthetic administered to it, the larger caterpillar died, and its hitherto attached friend was then observed to leave it and to make its way to the back of a living specimen. AN intimate connection subsisting between different animals is that known as commensalism; commensals being creatures which may be said to sit at the same table, but which do not prey upon one another. Of late years naturalists have become acquainted with numerous examples of this form of animal partnership, and in the newly issued volume of the "Transactions and Proceedings of the New Zealand Institute," a fresh instance occurring where they seem to be rarest, It is among marine animals, however, namely, among the higher animals, is re- that the phenomenon of commensalism corded. In one of the Chicken Islands, has been most frequently observed. The off the New Zealand coast, lately visited, remora is a feeble fish, little able to make a curious lizard known as the tuatara and its way alone in the world of waters, yet certain species of petrels were found in- there are few fishes which have a wider habiting the same burrows, apparently on distribution. It owes its success in life the best of terms. In rare cases the bur- to the powerful alliances it forms. One row, which consists of a passage two or of its fins has been transformed into a three feet long, ending in a chamber a sucker, placed right on the top of its foot and a half long, one foot broad, and head, by means of which it attaches itself six inches high, is the work of the bird; firmly to any passing shark, whale, or as a rule, however, the lizard is the ex- even ship - no doubt taking the latter for cavator. Each builds its nest on opposite | some huge sea monster. By these it is transported, without further exertion on | From the ease with which they allowed its part, over great distances, meanwhile themselves to be captured, they were evipicking up such food as may come in its dently unaccustomed to swimming far way. According to Beneden, the fisher- beyond the protection of the stinging men of Mozambique make use of the tentacles of the anemone. The holothuremora for fishing purposes. Passing a rians, or sea-cucumbers, are another group ring, to which a cord is attached, through of lowly marine forms which afford shelthe tail of the creature, they send it in ter to fishes. The eel-like fishes forming pursuit of any passing fish or turtle, and the genus Fierasfer have this habit; but so tenacious is its hold that the object of they are not the only commensals of those its attachment is usually secured. Few accommodating sea-cucumbers. Profes fishes are better fitted to succeed in the sor Carl Semper, when investigating this struggle for existence than the angler or subject among the Philippine Islands, fishing frog, which, hiding itself for the found shrimps and pea-crabs as well as most part in the mud of the sea bottom, the Fierasfer living within the respiratory hangs out its fishing-rod with tempting cavity and sharing in the food supply of bait, right over its capacious mouth. In a single holothurian. He further states the branchial sac of this fish, as found in that he has seen specimens which, in this the Mediterranean, an eel is said to re- matter, bore a considerable resemblance side, and to share in the abundant food to an hotel with its table d'hôte. A cosupply of the lucky angler. Several partnery, profitable to both parties, exists small fishes have also been found habitu between several species of crabs and seaally to lodge in the mouth cavity of a anemones. In the China seas there is a Brazilian catfish, sharing such food as the crab which invariably has the same spelatter may succeed in capturing. The cies of anemone on its back, while the marine enemies of the smaller fish are so latter, it is said, is never seen apart from numerous that it is only by retreating to the crab. By this association the norplaces inaccessible, or at least distasteful, mally sedentary anemone becomes as loto their foes that they have a chance of comotive as the roving crustacean, while survival. A favorite shelter with many the crab gladly bears the burden for the small fishes is the umbrella-like disc of protection its commensal fortress affords. the larger sea-jellies, the stinging proper- Further, there is the hermit crab, which ties of which probably cause them to be tenants a molluscan shell, but which also avoided by the other denizens of the deep. contrives to have a particular species of As many as twenty fishes have, according anemone always attached to its adopted to A. Agassiz, been counted swimming home. How friendly the two are was within the fringed margin of one of those shown by Mr. Gosse, for when he repulsating umbrellas. Dr. Collingwood, moved the anemone he found that the when sailing in the China seas, once ob- hermit invariably took it up again and served a large number of individuals of held it patiently in its claws, against the the sea-jelly popularly known as the "man- shell, for about ten minutes at a time, of-war," each of which had beneath its until it bad fairly taken hold again. There bladder, and protected by its long tenta- are other two species of crabs noticed cles, a cluster of about a dozen small lately by Professor Möbius, which have fishes. He also observed that while every the singular habit of taking a sea-anem"man-of-war" had its shoal, the fishes one in each claw and of thus carrying under small specimens of this sea-jelly them about. With their tentacles were small, while those under larger ones panded, these zoophytes probably serve were correspondingly big. The same to screen the crabs from the observation naturalist traveller was among the first to both of their enemies and of their prey, notice the existence of a fish-sheltering just as certain other crustaceans cultivate sea-anemone. He discovered on a reef a colony of polyps on their backs with the in the neighborhood of Labuan an anem-view, or at least with the result, of deceivone which, when expanded, measured fully two feet in diameter. Over this monster zoophyte there hovered a pretty little fish, which, when driven off, invariably returned to its former position. Suspecting some connection between fish and anemone, he began raking about with a stick in the body of the latter, and succeeded in dislodging six similar fishes from the body cavity of the zoophyte. ex ing the creatures for whom they lie in wait. Other instances might be given, such as that of the little pea-crabs found occasionally in mussels and other bivalve shells, which, in return for the protection afforded by the molluscan shell, gives its host a share of the food it captures. These, however, will suffice to show how widely prevalent commensalism is throughout the animal kingdom. |