175 pounds it is a good deal like hard work. I slowly worked my way up and whenever I was completely exhausted I rested, clinging tightly to the tree, while the sight of the great, glittering jewel above my head tempted me to make further efforts. At last by reaching far out I could just touch it; then one more tremendous struggle and I held it in my hand. I carefully loosened it, put it in my overalls pocket, and in less than a minute had slid to the foot of the tree. Then I took it out; I fairly shouted and capered about like a boy; I rubbed it against my cheek and talked foolishly to it. No miser ever gloated over his gold as I did over that magnificent snail. Years before I had found on a shell mound back of Chokolaskee in the Ten Thousand Islands a Liguus which until now was by far the largest I had ever seen. Sometime during its life this specimen had had a quarter of an inch of the tip of its shell broken off and it had soldered up the opening. But even with that, when I came to put it beside my Chokolaskee shell, this was longer, more solid, and had greater diameter. Counting in the broken part, my new shell is exactly three inches in length and one inch and nine-sixteenths in diameter. It is a glossy ivory white with faint bronzy green, revolving lines, which are more. distinct on its base, and it must be about seven years old, a veritable patriarch, since most of our Liguus do not live more than three or four years. This magnificent specimen amply repaid me for all the hardships of my trip.

From Windlys Island I worked my way along the railroad through Long Island and into the great Key Largo which has a length of nearly thirty miles, and at the little flag stop called Keylargo I took the train for home.

The greater part of the original forest of the keys has been cut-that along the upper part of the chain in

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order that pineapples might be planted. As soon as the roots of the trees decayed, most of the soil which covered the fields was washed down through the loose rock, and pines would no longer grow on it. Then the hammock sprang up again, this time a scrubby growth, filled almost solid with thorny trees, shrubs, and vines. In most places it is so dense that one cannot work his way through it and it is possible to progress only by hunting out the more open parts of it. The heat is almost intolerable and mosquitoes and sand flies swarm everywhere during the wetter part of the year. Most of the few residents are poor and live in small, badly constructed shanties. It is difficult to get entertainment, even the privilege of sleeping under a roof, no doubt because of the number of tramps and bad men who are found on the keys. But the whole region possesses a peculiar charm; it is a bit of the tropics, it has a rich and interesting vegetation which, with its rather meager dry-land fauna, presents some remarkable problems in geographical distribution and evolution. During the winter there are comparatively few annoying insects, the sky is marvelously clear and beautiful, the few clouds have a summery look, and the water is lovely with a hundred tints of green and blue. A vast marine fauna literally swarms in the seas, and for the naturalist no more attractive region exists in the United States.

Everywhere I went I was taken for a tramp-my appearance no doubt helping to create this impression; but in every place I stopped I was able to convince some one that I was all right. One evening I tramped into the little village of Plantation and applied to a woman at a decent-looking house for a night's lodging. She told me to go away and shut the door in my face. At another house the women ran in, but by persistent hammering on the door one of them came and told me that no one

in the hamlet would keep me, that a short distance down the beach I would find a house. I hid my bag and walked a half mile along the shore to find no house and concluded that she expected me to sleep in the sand. When I came back I spoke to an elderly man who stood in a door and asked to be allowed to sleep on his floor. He refused to let me come in and didn't want even to converse with me. Finally I asked him if he thought I was a tramp and he said he did. I pulled out a gold watch and asked if tramps carried things like that. Then I took out a roll of money and said, "Do tramps carry this?" His severe scowl changed into a smile and he said, "Oh, come in, I guess you are all right." He gave me a good supper and breakfast and we parted the best of friends. As I left he said, "I'll tell the folks here what a fine visit I had with the old tramp.'" At a little flag stop where the postmaster sold railway tickets I asked for one to a neighboring station, and the man said, "Have you any money?" I handed him a twentydollar bill and in surprise he said he couldn't change it. Then I counted. him out the exact amount and told him

that he mustn't always judge people by their appearance.

My trip was a complete success for it enabled me to solve several problems that I had puzzled in vain over before going. I added not a little to my collections and as usual found things in places where the books said they should not grow. All the scrub was glorious

with flowers-I have never seen such an array in the tropics. Two Echites, vines closely related to the oleander, had glossy leaves and charming flowers, the one sulphur-colored, the other rich yellow, and both should be introduced into cultivation. There were masses of a yellow-flowered Cassia and acres of a lovely morning glory with great purple, blue, or pinkish salvers. In the scrub its slender, half trailing, half climbing stems catch and trip whoever ventures into it, but whenever I gazed on its splendid masses of bloom I forgave it. In the early morning and late in the evening the moonflowers were as conspicuous as their blue-flowered cousins, the morning glories. Such tramps bring one into the closest contact and communion with nature, and renew one's health and vigor.

can Museum of Natural History

LTHOUGH the animal

A

and

plant life of small islands and

of island groups, particularly of those which are more or less remote or inaccessible, is characterized by the presence of fewer species than on the mainlands, these species are often peculiar and strictly limited in their distribution, or of especial interest to science for other reasons.

Islands have in many cases been the last refuge of species of animals and plants which were unable to maintain themselves against the more numerous enemies that beset them on the continents. Sometimes the islands have preserved some survivors of forms which used to inhabit larger areas of land, now submerged under the sea, a remnant of which the existing island represents. The more or less complete isolation of animals and plants living on islands restricts or altogether prevents their interbreeding with members of their species from other regions, and the variations they may develop from climatic or other causes may become fixed and permanent, resulting in the formation of the new species found nowhere else. Such islands often afford exceptional advantages for observing the processes of evolution, as the factors affecting these processes in such isolated species are often fewer and simpler than on the continents. There is no doubt that Darwin in developing his theory of evolution was influenced by the observations of island animals and plants made during his earlier years as a naturalist.

The relationships existing between the creatures inhabiting the various groups of islands and those of other

regions, and especially the presence or absence of terrestrial forms which could not easily cross wide stretches of water by any natural means, disclose facts about the geography of past geological periods and aid in determining when and where former land areas now submerged must have existed. In this way they have afforded a valuable check on the conclusions arrived at by geologists by entirely different methods, for while they indicate that many existing islands were formerly a part of some continent or of a much larger island, they lend no support to fantastic theories of vanished continents or former land connections across what are now extents of wide and deep ocean. Added to all this, the strange character and, in many cases, the great and increasing rarity or the recent complete extinction of some of these creatures lend interest to them from a more popular point of view also.

It is not only distant oceanic islands that possess such interest, since even those close to the shores of continents occasionally have certain peculiar species not found anywhere else, or they may afford, through their comparative inaccessibility and freedom from predatory mammals, safer breeding places for animals such as seals or sea turtles, or ground-nesting sea birds, than can be found elsewhere. There is no question that, but for the breeding places provided by the islands off the Atlantic coasts of the United States and Canada, many of our sea birds such as the gulls and terns and members of the auk family would by this time have been practically exterminated from this part of the world. The gannet, for instance,

one of the largest and most beautiful of our sea birds, now breeds on this side of the Atlantic in two island colonies only, both much reduced from their former size; fortunately these colonies have at length been taken under the protection of the Canadian government. On the coast of southern New England, the breeding colonies of terns and laughing gulls on Muskeget and a few other more or less inaccessible islands were able to persist during the years of persecution to which these birds were subjected for the millinery trade, and have served as centers of distribution for repopulating other parts of our coast with these beautiful species, now that protection is given them everywhere.

The survival of the heath hen on Martha's Vineyard is another striking example, while the development of a species of sparrow, the Ipswich sparrow, which appears to be confined in its breeding entirely to Sable Island south of Nova Scotia, although it migrates in winter to the mainland, affords an instance near home of the tendency of insular life to result in differentiating new species.

In another respect Sable Island, just mentioned, is of interest, for although it is but little farther north than Portland, Maine, its shores were in the early days of the settlement of America still inhabited by a herd of walruses, the most southern colony of that species of which we have any historical record.

Forty miles off the coast of Lower California, not very far south of the United States boundary, is a small island, Guadaloupe, remarkable in much the same way. It was probably the last home of an extinct species of fur seal, and possessed three or probably four peculiar species or very distinct varieties of land birds that have recently become extinct. But its chief interest lies in its being the last stronghold of the California sea elephant, closely related to the sea elephant of

the southern hemisphere. This animal formerly inhabited the coast of the mainland of southern California, as well as Lower California. It was supposed to have been entirely destroyed, when a small herd of about one hundred individuals was found still in existence in 1911 at Guadaloupe Island, so that even at that recent date, it would still have been possible to save this remarkable animal from extinction.

Unfortunately the rapid increase of human population and the commercial expansion during recent times, and especially the development of rapid and convenient transportation, have put an end to the immunity of these places from occupation or at least from frequent visitation by the most destructive enemy of nature that this planet has ever seen-civilized man. As a result, hundreds of the forms of animal and plant life peculiar to them have already become totally extinct, and each year that passes adds more to the list.

Some of the most beautiful of the birds of paradise are of very restricted range and have become nearly or entirely extinct because of their slaughter for the millinery trade. Members of many groups are on the list of extinct or threatened species, especially birds, reptiles, land mollusks, insects, and many trees and smaller plants. Their remote and isolated homes protected them against their natural enemies but do not avail against the unnatural ones that now beset them.

Our own Hawaiian possessions afford a good example of what is taking place on many island groups. The native land birds of Hawaii are remarkable for the large proportion of peculiar species and genera found in no other part of the world. A recent writer1 states that "Due to the operations of various malign influences, the native forests and birds have greatly diminished within historic times. 1 MacCaughey, in The Auk, January, 1919.

Many known species of plants, trees, and birds have become wholly extinct, and many others are on the verge of extinction. A time is speedily approaching in which the extinct avian species will exceed in number those still surviving." Farther on he says, "Oahu has been more completely despoiled of its native bird life than any other of the larger islands. More of the known Oahu passerine species are extinct than are living today. The Oahu elepaio [a small flycatcher] is the most abundant of the remaining native birds and is practically the only species commonly seen."

That this unpromising outlook is no exaggeration is proved by many other writers and observers. A study of Rothschild's account of the birds of these islands, although published nearly twenty years ago and based chiefly on collections and observations of considerably earlier date when conditions were better than at present, records 7 of the 70 indigenous birds considered peculiar to this group of islands as already certainly extinct, and a number already very rare, known, in spite of extensive collecting, by but very few specimens, while of the remainder only a comparatively small minority were widely distributed and common on one or more of the larger islands. The Hawaiian Islands are characterized also by the great number of land mollusks, one family, the Achatinellidæ, being almost restricted to those islands. and differentiated into a large number of species, some of them of extremely local distribution. Many are entirely extinct and others are becoming very uncommon.

A species restricted to one or more small islands for its habitat is at a disadvantage for many reasons some of which can easily be recognized:

First, because island species usually comprise but a small total number of individuals, even though being crowded

on a small island may make them ap

pear abundant.

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If many are killed it means a seriously large percentage of those in existence.

Second, some catastrophe, perhaps a natural one such as a volcanic eruption, but more often one in which man has some complicity, may wipe the entire species out. An example of this is the destruction of the greater part of the race of heath hens on Martha's Vineyard (which under careful protection had been increasing in numbers) by a single forest fire in May, 1916, so that the total extinction of the species is now probably only a matter of a short time. In the case of widely distributed species this could hardly happen. But if the breeding places of a species are restricted, even though it ranges widely at other seasons, it is exposed to the same danger. The Galapagos albatross breeds only, so far as is known, on Hood Island of the Galapagos group. If this breeding colony were destroyed we cannot be sure that another would be successfully established.

Third, a species confined to a small island has no place to escape to from enemies which it cannot resist, or from the destructive changes, such as deforestation, that man may bring about. On scores of islands, human occupation. has been followed by the destruction of every bit of the former forest growths, in many cases resulting in the complete extinction of some of the trees and other plants composing them, and of the birds and animals peculiar to them and dependent on them for food and shelter.

Fourth, the advent of man is invariably accompanied by the introduction of destructive animals, especially domestic cats, rats, dogs, hogs, and goats, and in warm climates often of the mongoose, to say nothing of noxious insects, weeds, and disease germs accidentally imported. The species thus introduced are apt to have many advantages over the native ones. They