Aiea pony i Mas (Ot Os sree x ee Latve i Be eh, oh Bie We ot Pes (a. My, ALBERT R. MANN LIBRARY AT CORNELL UNIVERSITY In lower Florida wilds; a naturalist’s ob Tai Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924003012832 Lower Florida Liguus SO OOS OS OE Be 0D) a Se Nw em Bw nN HO oe ag EXPLANATION OF FRONTISPIECE Liguus fasciatus testudineus Pilsbry. Brickell Hammock, Miami. Liguus fasciatus lineolatus Simpson. Totten’s Key, Upper Keys. Liguus solidus lineatus Simpson. Lignumvite Key, Upper Keys. Liguus fasciatus castaneozonatus Pilsbry, var. Paradise Key, Dade Co. Liguus fasciatus elegans Simpson. Island S.W. of Paradise Key. Liguus fasciatus roseatus Pilsbry. Long Key, Everglades. Liguus crenatus marmoratus Pilsbry, var. Brickell Hammock, Miami. Liguus fasciatus alternatus Simpson. Timb’s Hammock, Dade Co. Liguus fasciatus castaneozonatus Pilsbry, var. Key Vaca, Upper Keys. Liguus crenatus eburneus Simpson. ‘Timb’s Hammock, Dade Co. Liguus fasciatus hybrid. Paradise Key, Dade Co. Liguus fasciatus versicolor Simpson. Long Key, Everglades. Liguus solidus lignumvite Pilsbry. Lignumvite Key, Upper Keys. Liguus fasciatus roseatus Pilsbry, var. Long Key, Everglades. Liguus fasciatus castaneozonatus Pilsbry. Paradise Key. Liguus crenatus septentrionalis Pilsbry. Fort Lauderdale, Broward Co. (Reduced one-fourth in length) In Lower Florida Wilds A Naturalist’s Observations on the Life, Physical Geography, and Geology of the more tropical part of the State By Charles Torrey Simpson With Sixty-four Illustrations and Two Maps G. P. Putnam’s Sons New York and London The Rnickerbocker Press 1920 352386 COPYRIGHT, 1920 BY CHARLES TORREY SIMPSON To JOHN BROOKS HENDERSON FRIEND AND COMPANION OF MANY CRUISES AND SCIENTIFIC EXPEDITIONS, THIS BOOK IS GRATEFULLY DEDICATED INTRODUCTION HE following pages are the result of ob- servations and experiences in the wilds of the lower part of Florida during more than twenty years of residence in the region. From 1882 till 1886 I made my home on the southwest coast of the State and have lived near Miami since 1902.. When I first came to the State the greater part of Lower Florida was an unbroken wilderness, and during the time I have been here I have quite thoroughly explored the territory described in this volume both as.a col- lector and general naturalist. To-day most of its hammocks are destroyed, the streams are being dredged out and deepened, the Everglades are nearly drained; even the pine forests are being cut down. At the time when I first resided in the State flamingos, roseate spoonbills, scarlet ibises, and the beautiful plumed herons were abundant. Deer and otter could be seen at any time and the west coast waters were alive with immense schools Vv vi INTRODUCTION of mullet and other fish, while manatee were not rare. The streams and swamps were full of alli- gators; in fact the wonderful wild fauna of our region filled the land and the waters everywhere. It has seemed to me fitting that some record of this life should be made, in view of the fact that it is so rapidly disappearing—and forever. Already a number of species of our animals and plants are exterminated from this the only area in the United States in which they have ever been found. In writing of our animals and plants I have made no attempt to use the very latest scientific names applied tothem. Every newmanual changes a large proportion of these, for our scientific nomenclature seems to be in an unhappy period of transition. I am under great obligations to Mr. John B. Henderson for repeated cruises made with him in his dredging boat the Eolis, and for many col- lecting trips in Cuba, Jamaica, Haiti, and the Bahamas, where I was able to study much of the tropical life of Lower Florida where it originated; also for much assistance in preparing this volume. Dr. John K. Small, of the New York Botanical Garden, has been my companion and mentor during a great many collecting trips in our terri- INTRODUCTION vii tory, and has most generously placed at my dis- posal a large number of photographs made by him in the almost untrodden wilds. Mr. Charles Deer- ing has shown me unnumbered favors in making me a member of collecting expeditions on his boat the Barbee. Mr. Wilson Popenoe of the U.S. De- partment of Agriculture, Professor Frances G. Smith of Smith College, and Dr. Roland Harper have fur- nished a number of photographs and rendered val- uable assistance. Dr. E. H. Sellards, former State Geologist of Florida, contributed the map showing the Pleistocene subsidence and has made valuable suggestions. Mr. E. Ben Carter, Chief Engineer of the Florida East Coast Railway, has kindly allowed me to use the excellent map of a part of Monroe and Dade counties which was made from surveys for the extension of that road. The map accompanying the text of this volume was drawn by the author in pencil and inked and lettered by Mr. Forrest Clark. The fine work of the map of the East Coast Railway has been freely copied with the permission of Mr. Carter. Cc. T. 5. Lrtt_e River, FLorma, April 22, 1919. CONTENTS CHAPTER PAGE I—Tue BuILpING oF THE LAND . : I II.—Tue Froripa Keys : : - 32 III.—Tue Ten Tuousanp Isianps . - 59 IV.—CareE SABLE . : 4 ‘ . 75 V.—THE SOUTH SHORE OF THE MAINLAND 96 -VI—TueE EVERGLADES . : ; . 118 VII.—Tue PLantinc oF Our FLora - 143 VITI.— Tue Lure or THE PINEY Woops . 167 IX.—TuHeE ORIGIN oF THE HAMMOCKS - 190 X.—IN THE PRIMEVAL FOREST ‘ . 210 XI—ALONG THE STREAM : : . 233 (XII.—ALonG THE MANGROVE SHORE . 254 “Xdil— Tae Oren Sea Brace . wt; 276 XIV.—THE WonpDERS oF AJAX REEF . 301 XV.—TuHE SECRETS OF THE SEA A - 317 XVI.—TuHE Story oF THE LAND SNAILS . 335 XVII—TusE BEAUTY OF THE NIGHT . . 353 XVIII.—TuHE SURVIVAL OF THE FITTEST - 373 INDEX . ; a ‘1 ‘ - 395 ix ILLUSTRATIONS PAGE Lower Frioriwa Licuus (In Color) Frontispiece DIAGRAM TO ILLUSTRATE FORMATION OF SAND IsLANDS AND PENINSULAS : ; . 23 RacGepD CorAL LIMESTONE . ; : . 24 SMALL OVERHANGING CoRAL ISLET : . 24 YounGc MANGROVES GROWING ON NAKED Rock 28 Cereus peerinci (SMALL). A NEw Cereus. 48 GETTING OUT PLANTS OF CEREUS DEERINGI . 50 Tue Barszze EXPLORING Boat. . . §6 Yucca Auorro.t1a (SPANISH BAYONET) . . 58 GIANT MANGROVE WALL NEAR CAPE SABLE. 60 CHOKOLOSKEE ISLAND, TEN THOUSAND ISLANDS 64 Home, Sweet Home. A TypPicaAL PALMETTO TuHatcH House : ‘ : ; . 66 NativE Roya, PALM AT RoGErRs RIVER » 92 HzAD OF CHOKOLOSKEE RIVER . i - 74 East Care SABLE, THE Most SOUTBERLY PoINT OF THE MAINLAND IN THE U.S. - 76 xi xii ILLUSTRATIONS THRINAX WENDLANDIANA, ONE OF FLORIDA’S New PALMs . s : : ‘ Cereus pEeNTAGONUS, A Most VILLAINOUS Cactus . : i s . . P CEREUS ERIOPHORUS, EQUALLY VILLAINOUS Two DIAMOND RATTLESNAKES ; Z 3 ONE oF FLoRIDA’s NEw PALMS, ACOELORRAPHE WRIGATII 5 ‘i * a . . CABBAGE PALMETTOS, NEAR PUNTA GorDA, FLORIDA . : : ; z ¥ GREAT ORCHID, CyrropopiumM PUNCTATUM, IN FuLt BLoom . : : ; F : GETTING our NEw Patm aT Maperra Bay . VIEW IN EDGE OF EVERGLADES. EVERGLADES NEAR PARADISE KEY PARADISE KEY witH NATIVE RoyaL PALMS . PERMANENT SEMINOLE CAMP , 3 Part oF FAMILY or ToMMy JIMMY AT SEMINOLE Camp, ‘ : : : . . HamMMock SCENE aT “ THE SENTINELS”’ SworD or Boston FERN ON PaRADISE KEy . NEPHROLEPIS BISERRATA, A BEAUTIFUL SwoRD FERN 7 . PAGE ILLUSTRATIONS xiii PAGE BEAUTIFUL NATIVE SHRUB, TETRAZYGIA BI- CoLor, IN FuLL BLoom . . ‘ . 160 VIEW IN PINE Woops . s 3 ; . 168 DIFFERENT STAGES OF GROWTH OF DWARF PALMETTO ‘ ‘ ‘ - - . 168 UpPROOTED PINE SHOWING CONICAL Mass OF Roots. : ; é : ; . 186 UPROOTED PINE SHOWING ROCK TORN UP BY ITs Roots 5 . ‘ ; : . 186 VERY YOUNG HAMMOCK 3 : 192 YounGc HAMMOCK AT WATER HOoL-E, Lonc Key, EVERGLADES . ; ‘ : 192 View on ParapisE Key, LovELY SETTING OF Roya PALM . : : . : 204 PoLypoDIUM POLYPODIOIDES, RESURRECTION FERN ; ‘ j : , : . 206 Two Views OF DENSE TROPICAL FOREST IN Miami HAMMOCK . ; P : 210 DENSELY CROWDED, STRAIGHT TREES IN Miami HAMMOCK . ‘ F 214 Giant Gumspo LiMBo (BuRSERA GUMMIFERA) . 216 DENSE TANGLE OF TROPICAL VINES 220 Mout oF LITTLE RIVER. : f . 234 xiv ILLUSTRATIONS View HIGHER UP STREAM . j Curious Root GrowTH OF ANNONA. a BRACKISH STREAM REACH . : Fi F CUTLER CREEK AT JUNCTION OF FRESH AND BRACKISH WATER . : : : . Rocky SINK ON CUTLER CREEK . - RIVER CYPRESS ENTANGLED WITH STRANGLING Fic. Cypress KNEES GIANT MANGROVES NEAR LITTLE RIVER MAZE OF MANGROVE GRowTH AT LEMON CITY MANGROVES ARCHING OVER STREAM 7 : OUTSIDE VIEW OF MANGROVE SHORE . r SEA BEACH AT CAPE SABLE, SHOWING. RICKS. OF SHELLS . : ‘i . , EGG CAsE OF Furtcur PERVERSUS . ‘ ; LovELy REEF Fish (Asuperpur SAXATILIS) . CoraL REEF ON SOUTHEAST COAST OF FLORIDA Hocrisa (Lacunotaimus MAXimus) SHOWING CHANGES OF CoLorR. UNDERSEA PHOTO- GRAPHS , F ‘ . . . . BotToM OF TROPICAL SEA. GoRGONIA ACEROSA. UNDERSEA PHOTOGRAPH . Two SKETCHES SHOWING OUTLINES OF DREDGE PAGE 234 246 246 248 250. 252 254 256 258 260 278 284 304 304 312 314 318 ILLUSTRATIONS XV PAGE THE Eoris, DREDGING YACHT BELONGING TO JoHN B. HENDERSON ‘ . ‘ - 320 PoLYGYRA AURICULATA, THE APERTURE RE- MARKABLY CONTORTED TO PREVENT THE ENTRANCE OF PREDATORY BEETLES . . 336 Licguus FAsciatus, TWO VARIETIES. SNAILS ATTACHED TO BARK OF TREE DURING PERIOD OF AESTIVATION . : F . 352 OXYSTYLA FLORIDENSIS AESTIVATING IN HOLLOW TREE. : : : : ; . 356 GREAT BLUE LAND CRAB (CARDISOMA GUANHUMI1) 370 ACTUAL MOONLIGHT SCENE LOOKING ACROSS BIscAYNE Bay : ‘ ‘ : . 376 STRANGLING Fic, First STAGE. : . 382 STRANGLING Fic, SECOND STAGE . ; . 384 STRANGLING Fic, THIRD STAGE. P . 386 STRANGLING Fic, Last STAGE 4 3 . 388 Ficus BREVIFOLIA, BECOMING A VERITABLE BANYAN . ‘ : : : : . 390 MAPS SKETCH Map To SHOW EARLY PLEISTOCENE SUBMERGENCE . ‘ j ‘ At End SxetcH Map oF LOWER FLORIDA . ‘ At End In Lower Florida Wilds CHAPTER I The Building of the Land HE observant visitor in Florida will find much that is interesting and surprising; some things. indeed that may be quite beyond his comprehension. He _ will notice that there are no mountains or high hills, that the general region is flat and but slightly elevated above sea level. He will observe that the drier part of the State is largely. composed of sand sometimes blown into dunes; that the many sluggish streams have hardly any valleys, and that the greater part of the territory is covered with a monotonous open growth of long leaved pines, with here and there stretches of. denser forest composed of hardwood trees and shrubs, called ‘hammocks.’ Occasionally there is a swamp I 2 IN LOWER FLORIDA WILDS which may consist largely of gray cypress trees with swollen, conical bases, while scattered thickly over the swamp floor are blunt leafless stubs from one to six feet long, thrust up out of the mud— peculiar growths which spring from the roots of these trees. If the stranger visits the lower part of the State he will find in the interior a vast extent of wet, often inundated prairie with wooded islets scattered along its borders. At the north of this great swamp, the Everglades, is Lake Okeechobee, which during the rainy season overflows the entire prairie. A low rocky ridge lies between the Ever- glades and the Atlantic shore. It projects west- ward far into the swamp in southern Dade County, and finally disappears in the great prairie. This ridge is cut into numerous islands, and water from the Everglades passes through the channels be- tween out to the sea. To the southeast, southward, and southwest of the mainland is a long chain of islands, the ‘‘Florida Keys,’ which extends in a great curve to the south and west, ending far out in the sea with the Tor- tugas. The upper islands of this chain are long and narrow, running parallel with the Gulf Stream, THE BUILDING OF THE LAND 3 and are of coral formation. The lower islands are of oolitic limestone and many of them run almost directly across the axis of the chain. If the visitor is a botanist he will find that the flora of the south- east mainland differs decidedly from that of the upper islands, although but a few miles distant, and also that many plants of the upper chain are not found on the lower group. The observer will also notice that almost every- where along both coasts of the State and separated from the mainland shore by narrow sounds there is a series of long islands or peninsulas, generally parallel with the shore, composed of sand and often covered with vegetation. He will find that in the lower part of Florida the protected shores of these islands and of the mainland are usually bordered by a dense growth of mangroves standing high on stilted roots and often reaching well out into the water. These trees help in a wonderful manner to build up the land. If our visitor be a Nature lover he will ask why is this great area so low and flat; why are there no stream valleys; why should the State be pine covered with only here and there an island-like hammock? Why so sandy, and whence came 4 IN LOWER FLORIDA WILDS the sand: What causes the curious growth of the cypresses; how and. when were the Ever- glades and the great Okeechobee formed; how comes the rocky ridge along the eastern coast? Why do the keys parallel the Gulf Stream; why are the upper ones long and narrow and what caused them to trend in the direction of the chain while most of the lower ones range across it? What is the cause of the difference in the floras which are separated by only a few miles of swamps or shallow sea? Why do the mangroves stand high on stilted roots, often with no trunk at all at their bases? These and many other questions are asked by the inquisitive stranger, indeed by those who long have lived here. In this and following chapters Ishall attempt to answer most of these queries and to explain other things Floridian not easily under- stood at first. In some cases the. geologic evidence seems to be so completely obliterated that we can only guess at a solution; in others we must wait for more careful and complete investigation before we can reach very satisfactory conclusions. At some fairly remote period in geological time a great plateau was thrust up from the depths of THE BUILDING OF THE LAND 5 the sea by a folding of the’earth’s crust at the south- eastern corner of the North American continent. This plateau has an average width of about three hundred miles and is of very nearly the same length. Its borders everywhere slope rapidly down into the abysses of the ocean. The eastern half of this plateau, which is the more elevated portion and now projects above the sea, is the present peninsula of Florida. This peninsula is shaped very much like the handle of an old- fashioned pistol. The northern or ‘‘continental” part of the State somewhat resembles the short barrel of the same, which is pointed directly at the States lying to the westward. The tract of land at the mouth of the Apalachicola River might answer for a trigger case. I once called the atten- tion of an old Georgia cracker to this peculiar form, and after looking closely at the map for a minute while he slowly traced the outline with his finger he remarked: ‘‘Hit shore does look some like a pistol. Y'all don’t reckon they wanted to fight, do ye, when they laid hit out thataway?”’ The surface or topography of the State is, geologically speaking, quite new, there being within its borders no rocks observable older than 6 IN LOWER FLORIDA WILDS the Vicksburg group of the Upper Eocene. The presence of coal or carbonaceous matter has re- cently been reported from wells at a depth of about a thousand feet in Marion and Pasco coun- ties, and this would indicate that at the time the coal was formed the surface of that part of the peninsula (a thousand feet below the present surface) was elevated to at least a short distance above sea level. As there are no evidences of any violent disturbances throughout the entire area we may presume that for a long time after the deposition of this carbonaceous material there was a gradual subsidence, and that the land was slowly built up by marine deposits at about the same rate at which the whole was subsiding. The entire area of Florida south of a line from Tampa to Daytona is very recent, as it belongs to the latest of the geologic periods—the Quaternary. The region lying south of a line drawn from Cape Romano on the west to about Fort Lauder- dale on the east may be designated as Lower Florida and this includes practically all of the State which has any claim to being called tropical. It embraces all the territory occupied in Florida by the large Cuban and West Indian arboreal THE BUILDING OF THE LAND 7 snails with their beautiful shells and probably all the region in which a majority of the native plants have been derived from the Torrid Zone. It is true that the flora of the seacoast littoral for a considerable distance north of these two points has been derived from Middle America, but, as I show elsewhere, it is subject to occasional destruc- tion by frost. A few very narrow strips of West Indian trees and plants found immediately along the beaches on dry land for some distance up the peninsula owe their existence only to their im- mediate proximity to the sea. During early or middle Pleistocene time (geo- logically speaking, only yesterday) a considerable subsidence took place throughout the peninsula of Florida, and all the lower part of the State (to north of the Caloosahatchee River) was sunk below the level of the sea. Most of the rock of the southern part of the State was formed under water during this period of depression. If, by any possibility, any of it had been above the ocean before this time, the flora and fauna in- habiting it were either drowned or driven to the northward. The story of the building of the land, so far as we need to trace it, may begin with 8 IN LOWER FLORIDA WILDS this Pleistocene submergence—this depression of *‘yesterday.”’ "It was probably at this time that the great coral: reef along the Floridian border of the Gulf Stream was started, and grew until.it finally appeared at the surface of the sea. After being worked over by wave and storm action and with slight further elevation it formed and then became the present Upper Keys. This reef lay on a bank at some distance from what was later to become the main- land and was nourished by the warm, food-laden waters of the great ocean river that swept along it. When it had been built up to near its present height another coral reef or fringe began to grow up outside it and this is the present outer reef, which we shall visit in a later chapter. During this same period of subsidence extensive beds of shallow water limestone were deposited over much of what was later to become our present Lower Florida. One of these limestone beds, an oolitic, covered the area which has since become the present region of the Lower Keys, and it is quite possible that this same formation extends to and includes all the present southeast coast where the rock is called by geologists the ‘‘ Miami lime- THE. BUILDING OF THE LAND 9 stone.” This ‘‘Miami limestone” is usually believed to be of coral formation but it is really a shallow water oolitic limestone with a few corals mixed in here and there. On the southwest coast the ‘‘Lostman’s River limestone’’ was probably laid down at this time and in the area now the interior of the Everglades a similar shallow water limestone was deposited. Towards the close of the Pleistocene (geologi- cally speaking at this morning’s dawn) a period of elevation took place. Then for the first time the lower part of the State assumed essentially its present form, covering much the same area it does to-day. It is probable that during the time of this gradual elevation the rocky ridge (already referred to) lying between the Everglades and the Atlantic was built up. Beginning at Little River, though with occasional outcrops for some distance northward, and extending to its extreme southwest end, this ridge is composed of a soft oolitic limestone and is but a few miles wide, now broken into a series of ‘‘islands.”” It reaches well down into the Everglades, then turns to the westward, then to the southwest, and finally ends within five miles of Whitewater Bay. The water 10 IN LOWER FLORIDA WILDS of the Everglades drains freely through this porous rock, sometimes in wide prairie-like channels be- tween the ‘‘islands”’ and sometimes it appears as springs on the eastern side of the ridge. This rocky ridge, which Dr. John K. Small has appro- priately called ‘‘The Everglade Keys,” is surely a series of ancient sea beaches, formed one after the other during the gradual elevation of this area. This is indicated by the strata being greatly cross bedded throughout a considerable part of it. In places between these old beaches the water must have been sheltered and quiet, as is indicated by many fossil bivalve shells found clinging together in a natural state. A northern sandy part of this ancient shore line overlaps the rocky ridge and was deposited at a later time. This ridge was the great highway over which plants and animals from the American tropics migrated northward and those from the north came southward. In all probability the Everglades (which we shall personally inspect in another chapter) began to develop at about this time. The upper part of the chain of keys, doubtless in process of formation before the time of this uplift, was then thrust up, THE BUILDING OF THE LAND It and many of the corals, because of exposure to the atmosphere, were killed. The sea broke up the exposed surface of the reef, worked it over, and scattered the debris, forming thus a wide foun- dation for future growth of coral. Samuel Sanford has claimed that this, or some more recent or subsequent uplift, carried the land to perhaps two hundred feet above its present level. Had there been so great an elevation all Lower Florida, including the keys, together with the pres- ent bays and sounds necessarily would have been continuous dry land. As the area is not large, its surface flat, its structure quite uniform, and its climate throughout, especially near the sea, quite the same, it seems certain that had so great an uplift ever taken place there would be to-day but one common assemblage of dry-land animals and plants throughout, or in the warmer part, at least, of the region. There can be no doubt that most all of the species would have been distributed over the entire territory. This, however, is not the case. Actually we find three more or less circumscribed areas of dry-land life occupying Lower Florida. First, the Lower Keys are inhabited by an almost strictly tropical flora, and within their borders there are 12 IN LOWER FLORIDA WILDS about one hundred species of native plants which are found nowhere else in the United States. Liguus solidus, a large, beautiful arboreal snail, exclusively occupies these islands and has formed several well marked subspecies, but it does not occur on the mainland. One particular form which may have originally sprung from it is found on Lignumvitz and on Lower Matecumbe keys of the upper chain, but it probably reached these islands by drifting from the lower chain. Another large tree snail (Oxystyla resus) has evidently de- veloped on the Lower Keys and is only found else- where on Key Vaca, an island of the upper chain but lying close to the lower ones. Hemitrochus varians, a finely colored Bahaman snail, is abundant on the southeast coast and Upper Keys, but is not found on the lower ones. A native cotton rat and a cotton mouse, which I shall mention elsewhere, occur abundantly on the upper chain of islands but never on the lower. So far as we know, no mammals are indigenous to any part of the lower group. The mainland of the Miami region, including the rocky ridge just mentioned, ‘has a mixed flora, a majority of its species being migrants from the THE BUILDING OF THE LAND 13 American tropics. These are, to a very consid- erable’ extent, identical with plants found on the Lower Keys. A little over a third of its flora is temperate and warm temperate, having migrated by land from the northward since the beginning of the land elevation. Only a few of these hardier northern plants occur on the keys. It is probable that the Lower Keys formed a single island during the time of this uplift, at. which time the Miami mainland was first elevated above the sea. For a long time seeds and animals were carried north- ward by the Gulf Stream and established simul- taneously on both of these land bodies while the present Upper Keys were only a living coral reef. In all probability the present south shore of the mainland was under water at that time and the same is doubtless true of the present southwest coast. Had the Upper Keys been elevated above the sea at that time they would have proven a rather effectual barrier to the landing of tropical life along the old Miami shore. The Upper Keys, the extreme southern part of the mainland, and the lower southwest coast are inhabited by a common assemblage of plants, and, to a considerable extent, of animals, which differ 14 IN LOWER FLORIDA WILDS somewhat from those of the Lower Keys and the Miami mainland. There was an old landway, now wholly submerged and quite dissolved away, which reached across from Lower Matecumbe Key to the mainland east of Flamingo. Before the Florida East Coast Railway dredged a chan- nel across the mud flat back of Matecumbe it would have been possible by following the tor- tuous shoals actually to wade from it to the main- land near Joe Kemp’s Key, a distance of fully thirty miles, in water nowhere more than two feet deep. In fact there is now an extensive series of shoals lying along the inside of the Upper Keys from Duck Key to Largo (a distance of twenty-five miles) which stretches all the way across to the mainland with only here and there an enclosed basin of six or seven feet depth. For the most part, these shoals are continuous. East of these shoals at the head of Florida Bay, an uninterrupted body of water from six to seven feet. deep extends across from Key Largo to the mainland. This together with the extensive swamp to the northwest of it has acted as a barrier to the passage of dry-land plants and ani- mals from the Upper Keys and also from the ham- THE BUILDING OF THE LAND 15 mocks along the south shore of the State over to the rocky ridge east and south of the Everglades. The northern end of the upper chain of keys is not more than eight miles distant from the rocky ridge on the Miami mainland. Key Largo has been connected with the mainland until recently but the connection was a swamp never sufficiently dry to permit the passage of upland forms of life. Notwithstanding the nearness of these two bodies of land and the fact that they are only separated by the shallow waters of Biscayne Bay, Card and Barnes sounds I feel safe in asserting that there has never been an elevation sufficient to unite them as dry land since the present life reached their shores. Nor, on the other hand, has there been any subsidence great enough to drown out our dry-land flora and fauna since they were first es- tablished. I do not believe that since the first Pleistocene elevation there has been twenty feet of change in elevation in all Lower Florida. At least sixty species of tropical plants are found on the Upper Keys which do not occur on the Miami mainland and a large temperate and warm temperate flora grows on the latter which is entirely absent from the former area. There are 16 IN LOWER FLORIDA WILDS more than 140 species of tropical plants common to this mainland and the Lower Keys which do not occur on the Upper Keys at all! 1 can conceive of no better evidence that the Miami coast and the Lower Keys (which are likely of the same geo- logical formation), though they were perhaps never actually connected, were above the sea and were receiving life drifted from the American tropics a long time before the Upper Keys had become dry land. If I amcorrect.the Lower Keys should be far richer in tropical life than the upper ones. This is in fact the case for 440 such species of plants have been reported from the former area as against 265 from the latter. Yet there is but little dif- ference in the extent and surface features of the two groups of islands. It is doubtful that they have ever been connected by dry land. The Moser Channel lying west of Knight’s .Key (of the upper chain) and eastward of the lower chain carries through a full nine feet of water from the Gulf of Mexico to the Florida Strait, and this channel has probably separated the two groups of islands or keys from the time when the present tropical flora and fauna first began to arrive. The distribution of the animals of Lower THE BUILDING OF THE LAND 17 Florida is not so well known as is that of the plants, but it is certain that we have many tropical species of the former within our borders. I have seen a large collection of butterflies made near Havana and more than half of its species are also Floridian. I do not know that any naturalist has identified all our other insects. We have about forty species of land and fresh-water mollusks in Florida of tropical American origin and of these at least a dozen have developed into distinct species since they arrived here. It is probable that when our flora is fully investigated quite a thousand species of tropical plants will be found in Lower Florida, and of these, a considerable number, perhaps fifty, will prove to be endemic, that is they have developed into new forms since landing on our shores. It has required a long time for the attainment of such results, for the process of establishing a flora and fauna by drifting and migration must necessarily be a slow one, and the development of species takes much time. Ages have been re- quired for all this and it is not unlikely that twenty or twenty-five thousand years have elapsed since the mid-Pleistocene elevation began. 2 18 IN LOWER FLORIDA WILDS Some time after this mid-Pleistocene elevation there came a second subsidence, but only of a few feet. Along the low, rocky bluffs in and just north of Cocoanut Grove, erosion marks made by the surf are plainly visible. The same evidences may be seen in the great hammock south of Miami, its eastern rocky wall having been the sea- shore at the time of this slight subsidence. Now the southern end of this wall is quite a distance back from the bay though at the Punch Bowl the bluff comes out to the shore. The same erosion marks may be seen on a bit of rocky bluff on the north side of Little River, and along the walls of Arch Creek. There are old beaches on which long dead (but specifically recent) sea shells are scattered, in several places back from the western shore of Biscayne Bay and again at Boca Raton, north of Fort Lauderdale. These are six or seven feet above tide and correspond in height with the surf marks on the bluffs near the Punch Bowl. A similar shell beach on Big Pine Key of the lower chain, would indicate that the sub- sidence was not so great there, as it lies about three feet above the ocean. These old beaches mark the limit of the second subsidence and during THE BUILDING OF THE LAND 19 the greatest depression the sea entered the eastern border of the Everglades. At the same time the reef (which later became the Upper Keys), was still further built up and developed. This second subsidence was followed by a second period of elevation, during which the corals of the reef slowly died and the sea again destroyed the surface of the reef, piling up debris, scattering the looser materials, and reshaping it into islands of coral rock. The reef was finally elevated sufficiently for the seeds of dry-land plants to germinate upon it and establish a flora. Lower Florida mainland was doubtless slightly higher at this time than it is at present, sufficiently so that the old land passage elsewhere mentioned from the mainland to the Upper Keys existed. A third slight subsidence followed and is prob- ably continuing at present. Now the old landway just referred to is submerged and its remnants are being destroyed by the solvents of the sea. While making excavations in a brackish swamp on my place I found stumps and trunks of live oaks and other trees below the present level of high tide, and these were undoubtedly in the localities where they grew. Sanford mentions seeing a thick 20 IN LOWER FLORIDA WILDS stump in gray marl on the southwest coast cov- ered by water at high tide. He believes, as I do, that there is evidence at Cape Sable of a slight recent subsidence. On the outer shore opposite Lemon City the sea at one time since I have lived here, encroached on the sandy shore and un- covered peat of an old mangrove swamp which is now submerged at low tide. Along the south coast of the mainland the sea is eating into the beach to such an extent that mangrove and buttonwood trees are found for some distance out into the bay. Finally the great area of mangrove swamp which covers many thousands of acres in the Ten Thousand Islands and along the south and southeast coasts would seem further to indi- cate that a subsidence is taking place. This need not cause owners of bay front property in Lower Florida any serious alarm since it is probable that the mangroves and other shore vegetation are building up the land as rapidly as it subsides. Beginning at the southeastern shore of Vir- ginia, thence extending into Dade County, Florida, again appearing in Lee County, on the southwest coast of our State and then continuing with THE BUILDING OF THE LAND 21 occasional interruptions around the Gulf of Mexico to Yucatan, is a series of long, narrow, sandy islands and peninsulas lying parallel with the mainland shore and at no great distance from it. They are usually low; rarely rising higher than the limits of a storm tide, though in places they assume the character of sand dunes, with a little greater elevation. Between these islands and the main shore there are usually shallow lagoons some- times called rivers, though their water is salt or brackish. In some places these lagoons fill up with sediment with little or no water remaining and thus form brackish swamps. It has often been asserted that these sandy coastal islands result from ocean currents running parallel with the shore which carry and deposit sand in long, narrow bars, constantly adding to these bars at the end where the retreating water leaves them. While this may be true in some cases I do not believe that the action of such currents alone has formed most of theseislands. In some instances these narrow land bodies run parallel with the shores of bays where it seems unlikely that any ocean currents would sweep along the deeply incurved beaches. Besides this, such long-shorecurrents could only build up thesand 22 IN LOWER FLORIDA WILDS to the level of an ordinary high tide, while these elongated bars are generally considerably higher. It seems more probable that these peculiar forma- tions are caused by the action of the ordinary tides aided by occasional storms which sweep in upon the shore. Wherever a sandy sea bottom slopes very gradually from the beach the waves stir up the shifting sand for a long way off shore espe- cially when strong tides are coming in or when high winds blow towards the shore. This dis- turbance of the water,—the ground swell, sweeps up the sediment and loose sand at a depth of several fathoms and often from a distance of some miles out. After severe storms during which the wind has blown towards the land, immense num- bers of fish living in water of considerable depth are occasionally cast upon the beach, their gills choked with sand and mud. The water has been so greatly disturbed they have perforce breathed in the silt which they could not eject and have literally drowned. As the shore is neared and the water becomes more shallow its landward movement is accel- erated, so that in some places and under certain conditions it rushes in with considerable speed. Diagram to Illustrate the Formation of Sand Islands and Peninsulas a, a, a, sea level; b, b, b, sea bottom; cc, shore; d, d, ridge of sand formed off shore along slack,water line, e. Arrows show direction of currents, THE BUILDING OF THE LAND 23 In Hawaii the natives with surf boards swim out from just such shores and upon the wave crests are swept in with great rapidity. At the beach the wave-formed current turns back sea- ward, retreating underneath into deeper water, rapidly at first and more slowly as the depth in- creases. This backward movement is called the undertow, and swimmers are sometimes carried by it out to sea. This outgoing undertow rapidly slackens because of its friction against the bottom and also against the incoming water above, and ata certain distance from the shore, by reason of this friction and of the increasing depth, it ceases to advance and mingles with the comparatively slow moving, incoming tide. All this water contains silt and often the coarser sand, but only a little of it is deposited between the beach and the line of slack tide well off shore because of its too rapid motion between these two points. Naturally a considerable quantity of sand and mud must be released and deposited where the undertow slack- ens and ceases to flow. Thus a ridge of silt begins to form along the line of these mixed currents and slack water, parallel to the shore and at some distance from it. Once 24 IN LOWER FLORIDA WILDS begun the ridge acts as an obstruction to the in- coming and outgoing tides, and more and more material is deposited on and against it from both within and without. Finally the ridge builds up to the level of high tide and a bay or so-called “river” isa result. More sand is heaped against the outside of the ridge during very high tides or incoming storms until eventually it becomes a long island or peninsula, sometimes ten feet or more in height. The wind may sweep the sand into dunes; seeds and the flotsam of the sea are cast upon it and the island is covered with a mantle of vege- tation. Such a tidal peninsula has been formed between New River Inlet (near Fort Lauderdale) and Cape Florida, and the upper end of Biscayne Bay is the resulting ‘‘river’’ that lies behind it. Beginning at Snake Creek at the upper end of the bay and extending for some distance to the north- ward the space back of the tidal land has.be- come filled with vegetable muck until it is now a swamp. There are generally open channels at intervals between the bays or ‘“‘rivers’’ and the open sea, through which the tides rush swiftly. Where the sea bottom slopes away very grad- Upper View. Ragged Coral Limestone, Shore of Pumpkin Key, Upper Keys Photo by Dr. John K. Small Lower View. Small Coral Rock Key near Marathon, showing Erosion of the , Sea and Overhanging Rock THE BUILDING OF THE LAND 25 ually often a second ridge is formed outside the first. Such may be observed at Cape Canaveral. Now as against this constructive action of the sea in land building and extension there are many opposing forces of destruction to offset it. Upon every shore a contest is being waged by Nature’s forces to build up, on the one hand, and extend the land seaward, and to destroy the land, on the other hand, and bury it beneath the sea. Thus the constant changes we may see from year to year along any beach. Destruction of the land is chiefly caused by erosion and by the solvent action of both fresh and sea water. The surf is constantly bombard- ing the rocky beaches with crashing wave volleys while insiduously dissolving away the rocky shore by the chemistry of its waters. Even the spray thrown back from the shore, and forming pools in the depressions in the limestone, gradually de- stroys the hard rock much as some corrosive acid would do. Between tides the water constantly erodes and dissolves the limestone rock, often causing a shelf to overhang for fifteen or twenty feet. From above, the little holes of erosion be- come eaten through, and every wave that thunders 26 IN LOWER FLORIDA WILDS in sends up spouts of solid water and spray. By and by the overhanging shelf becomes weakened and finally breaks off by its own weight or from a particularly vicious blow from the sea. I know of no word or combination of words which would properly describe the sharpness, the raggedness and jaggedness of some of these rocky beaches along the Upper Keys. Compared with them the rocky road to Dublin is a smooth, macadam turnpike. Most of the rock of these keys is very porous and the water from the heav- iest of rains immediately sinks through it to tide level, dissolving always more or less of it as it passes along. Whenever there is a high tide on the ocean side there is sure to be a correspondingly low one inside or in the bays. Then especially strong currents of sea water sweep through and under the rock from the flood to the ebb side taking heavy toll of rock substance as they pass. I have counted as many as twenty streams of sea water issuing from the outer side of old Rhodes Key in a distance of as many rods, at a time of low tide on that side of the island and high tide on the other. Some of them were mere trickles but a few were good-sized currents. THE BUILDING OF THE LAND 27 Eventually a weakened roof collapses over one of these water passages but the debris is soon dissolved and washed out and in time an open passage from ocean to bay is formed. There will be deep holes and shallows in these passages, and along their banks mangroves may find lodg- ment, sometimes even on the bare rock. The tides rush through the newly made passage con- stantly eating away its banks until the two sides are widely separated. Many if not all the keys have been more or less divided in this manner and are still being worn away. The Ragged Keys, a set of rocky islets at the northern end of the chain (and most appropriately named), are striking examples of this scouring and dissolving power of the sea. . According to A. J. Sands and Otto Matthaus, both long residents of the region, Ragged Key Rock was, but a few years ago, about fifty feet across and supported trees and shrubs. The sea completely undermined it and then a severe storm completed the wreck. Now there remains but a small rock visible at low tide. It is not unlikely that within a few centuries past this now submerged rock was a part of a long island lying to the south of it. The present gradual sub- 28 IN LOWER FLORIDA WILDS siding of this region certainly aids the sea very materially in the destruction of the land. There is no reason to doubt that the bays along the south and southeast mainland coasts are slowly deepen- ing and encroaching upon the land. The sea water cannot dissolve all the limestone which it destroys but it leaves a small residue. This residue serves to augment the mud flats of the bays and tidal channels. This is well seen at the mouth of Cesar’s Creek and in the several passages between Largo and Elliott’s keys. In his Observations upon the Floridas, published in 1823, Charles Vignoles stated that Key Largo was a peninsula, connected with the mainland by a portage of six boat-lengths, though now a navi- gable channel separates the two. A cotton rat (Sigmodon hispidus) and a cotton mouse (Pero- myscus gossipium) both dry-land and swamp-fre- quenting animals, but not swimmers, are found on Key Largo, which would indicate that there was formerly a land connection between the mainland and the island. It is quite probable that the water passage separating the two bodies of land may be due to both solution and subsidence. The former connecting neck of land did not, how- dadiey ‘WW “y Aq oloug Avy oquinoeyey IoMOT ‘HOY [e1OD pexeN] UO Zurmory soaorsuep Funox THE BUILDING OF THE LAND 29 ever, permit the migration across it of the highland vegetation as the mainland just back of it was a great swamp. The dissolving of the soft limestone rock is nowhere more evident than in the pine woods bordering the Everglades. Before the recent drainage of this region the glade lands were cov- ered with fresh water throughout the rainy sea- son, and sometimes during the entire year. Rain water absorbs a considerable amount of carbonic acid or carbon dioxide as it falls through the atmosphere, and much more is added to it by decomposing vegetation. This Everglade fresh water often extends well out over the low pine woods and has carved the rocky forest floor un- til it is quite as rough and ragged as is that of the keys. Hence the irregular sinks and many potholes, and the uneven surface of villainous knife-like edges which render walking over it a really hazardous undertaking. In places the honey-combed rock becomes so undermined and rotten that it breaks under the tread, but woe unto him who falls upon it! So level is the general face of the country that surface water sometimes seems undecided which 30 IN LOWER FLORIDA WILDS way to flow. It must then go downward through the porous rock, eventually reaching the sea by underground channels. Into these the tide often flows back for long distances. Wherever along the coast there is a slight ele- vation it is dignified (in a double sense) by being called a ‘‘bluff’’; every gentle swell of the surface is at least some kind of ‘‘heights’’; some even apply the name ‘‘mount”’ to their estates. Verily all things are relative! ; The widespread mantle of sand which covers most of the drier part of the State is composed of grains of quartz. On the coasts it is mixed with finely broken marine shells. The problem of the origin of this siliceous sand is an interesting one. Just how it came to be dispersed over the whole region is also of interest. Doubtless it is of northern origin and some of it was washed down by the rivers of the Appalachian mountains. The cold return current which sweeps southward along the Atlantic coast constantly brings cargoes of it; the sea throws it up on the land and the winds disperse it. Some of it is a residue from limestone rocks formerly covering parts of the State but now destroyed by action of the air and water. The THE BUILDING OF THE LAND 31 blanket of sand reaches as far south as Miami and Cape Florida on the southeast coast, and to Cape Sable on the southwest. But the manner in which it has been so generally distributed over Florida in almost level beds, is probably not well understood. At these two points the siliceous sands rather abruptly cease and to the south the sand of the beaches is composed entirely of broken bits of coral, shells, and other marine growths,—with little or no trace of quartz or of the older rocks. There have been no violent convulsions, no sudden or great disturbances during the geological history of Florida since the original uplift of the Florida bank, yet a ceaseless construction and destruction of land have been goitig on within its limits. The new land formed yesterday of silt washed down by streams, by elevation or by the deposition of vegetable matter, is being dissolved to-day by carbon dioxide, worn away by stream or surf action or carried below by subsidence. CHAPTER II The Florida Heys ET us in fancy take a very large pair of dividers, setting one point at Cape Romano on the southwest coast of Florida, and the other at Miami and then sweep the latter point first south, then southwest, and finally west until it reaches a spot west of south of the central point. We have thereby fairly accurately marked the curved axis of a group of islands called the “Florida Keys.” From Miami another but irreg- ular curve to the south and west nearly coincides with the southeast and southern coasts of the main- land. These two curved lines begin together on the east coast but diverge as they make to the south and west so that when Key Vaca on the first line is reached, Cape Sable, which lies due north of it on the second line, is twenty-eight miles distant. The horn-shaped area of shallow water between which separates the keys and the mainland is the 32 THE FLORIDA KEYS 33 Bay of Florida, Blackwater Bay, Barnes and Card Sounds. The axis of the great island chain corresponds closely with the curve of the southern edge of the ‘‘plateau,”’ the foundation of the Peninsula of Florida. It also marks the northern border of the Gulf Stream. The true keys begin at the north with Soldier Key, a little islet about eleven miles to the southward of Miami, though the reef rock reaches just a bit north of this island. They extend to the Tortugas, the westernmost island of the chain and distant from the first (on the axis), about one hundred and eighty miles. The islands vary in size from the tiniest bit of rock, sand, or mud, often crowned with a green boquet of man- groves, to Key Largo, almost thirty miles long. The crowning elevation is in the ‘‘knolls” at Windley’s Island. Their dizzy height of eighteen feet in so flat a region gives them by contrast a real dignity. Between the chain of keys and an outer reef paralleling it lies the Hawk Channel, a long, narrow body of shallow water with a maximum depth of six fathoms, and >. width of from three to six miles. This channel eatends from near Cape 3 34 IN LOWER FLORIDA WILDS Florida to the Marquesas Islands. The reef is largely formed of living coral, and is, no doubt, an incipient chain of keys. With a slight uplift a soil would soon be formed on the exposed reef, seeds would be washed upon it, a forest would grow and a second chain of keys, much like the present one would be the result. | Many years ago Louis Agassiz, the distinguished naturalist, studied the Florida Keys. He main- tained that they, together with the entire southern part of Florida, were made up of coral reefs. He stated that the ‘‘shore bluffs’? along the south part of the mainland were simply an ancient coral reef; that after crossing a flat expanse of land called ‘‘The Indian Hunting Ground”’ a series of elevations was reached which bore the name of “The Hummocks”; that seven such reefs and interspaces had been traced between the ‘‘shore bluffs’” and Lake Okeechobee. He further be- lieved that the entire peninsula was of coral for- mation and made an estimate of its age based on the normal growth rate of living corals. There is no real foundation for these statements or theories, and if Agassiz had actually explored the mainland he certainly would have fallen into \ THE FLORIDA KEYS 35 no such error. There are no bluffs anywhere along the shore. I have been inland for a con- siderable distance from Cape Romano, Chokolos- kee, Rodgers River, and other places along the southwest coast; and I am very familiar with Cape Sable and the country back of it; with Coot, Madeira, and other neighboring bays, and I have explored Cuthbert Lake along the south coast and there is no evidence of coral growth at any of these places. The Florida East Coast Railway enters the mainland on the southeast coast and runs through an unbroken swamp to Florida City, fif- teen miles from the shore. The Flamingo region is alluvium and that to the east of it is marl, Cape Sable is a sand bank based on an old mangrove swamp. The Ten Thousand Islands are swamp with a few artificial mounds. Nowhere is there coral. Because of its eminent originator this theory of the development of Lower Florida has been very generally accepted. The only possible foundation it could rest upon is the fact that a part of the keys and all the outer reef are built of coral. A glance at the charts of the Florida Keys shows that the islands of the upper part of the chain 36 IN LOWER FLORIDA WILDS are long and narrow and that their axis is parallel with the edge of the Gulf Stream while the islands of the lower group are very different both in shape and arrangement. The eastern islands of the lower group are somewhat elongated but they lie across the axis of the chain. Those on the west are very irregular in form, constituting a small but amazingly complicated archipelago, in which there seems to be no systematic alignment whatever. A careful inspection of the charts will also show that the upper chain of islands apparently blends with the lower group leaving as doubtful in their true relationship Bahia Honda, the West Summer- land Keys, a narrow strip of land belonging to the southern end of Big Pine Key, and the New- found Harbor Keys. With the latter keys, however, the upper chain seems positively to end. The upper islands are an old coral reef formerly built along the edge of the great peninsular pla- teau. It was subsequently raised slightly, so naturally the chain consists of long, narrow islands running parallel with the Gulf Stream. I feel sure that the lower group of keys is a remnant of what was once a single large island which lay along the THE FLORIDA KEYS 37 northern part of this great ocean river and which had been raised above the sea by the first Pleisto- cene elevation. It extended from East and West Bahia Honda Keys (on the east) to Key West or possibly even further west, and from the Content, Sawyer, Johnson’s, Mud, West Harbor, and Northwest Boca Chica Keys (on the north) to the inner edge of the Hawk Channel (on the south). While this large island was entire, and perhaps even since that time, various animals and the seeds of tropical plants were brought to it, largely by the Gulf Stream; these became colonized and finally generally distributed over it. At the time of the second depression (during later Pleistocene) the island subsided slightly, but not sufficiently to drown out completely its dry-land life. Its eastern end was lowered until the waters of the Gulf of Mexico occasionally swept over the lower portions during severe northers. I found sea shells of existing species scattered abundantly along the southwest shore of Big Pine Key at a height of about three feet above tide, and these probably marked the extent of the greatest de- pression. The water which was driven across the low land scoured out a series of parallel chan- 38 IN LOWER FLORIDA WILDS nels having a north-northwest, south-southeast direction and it is also likely that it formed pas- sages under the rock which later became open tidal streams. Johnson, Little Pine, No Name, Big Pine, Torch, and Summerland Keys are long, narrow islands lying between these channels and conforming with them in general direction as do several bars which lie just east of these keys. The tidal periods differ in the Gulf of Mexico and in Florida Strait, hence there is a rush of water from one side to the other, which, even under normal conditions operates always to dissolve the rock and scour out the debris. The westernmost of the larger north and south channels is between Sugar Loaf and Cudjoe Key and to the westward of this there is a different arrangement of land and water. Apparently this western area did not subside sufficiently to permit the water of the Gulf to drive across it so freely, hence, there are but a few small channels cut through. One channel seems to be now forming east of Big Coppitt and also another one west of Boca Chica. There are two or three other rela- tively small openings. Several years ago in company with Dr. Pilsbry THE FLORIDA KEYS 39 of the Academy of Natural Sciences of Phila- delphia I was storm bound during a very severe norther at the mouth of Pelot’s Creek, a narrow passage east of Boca Chica. For three days the sea water, filled with silt to a coffee color, and bearing floating timber and all manner of rubbish, was driven through this little channel at the rate of ten miles an hour. Although it was early in April the strong wind was bitterly cold and we were obliged to get our launch into that creek where we would find the only shelter. It took three of us with the tow rope and the full power of the engine to get the boat in, and once or twice it very nearly broke away. The third day of our enforced stay Dr. Pilsbry became anxious to get to Key West en route home, and against the boatman’s protests we made the attempt to leave. With a line from the stern to a man- grove we cast off forward and once fairly in the stream and with the engine full ahead we shot down the channel at railway speed. The wind had driven the sea a quarter of a mile away from the beach but through the channel across the beach we were swept at a terrific rate. The bow struck a bar and we whirled around like a top. 40 IN LOWER FLORIDA WILDS Before reaching the sea, we struck something side-on in a broadside rush that threw some of us overboard. There we remained miserably ex- posed to the fury of the wind for six or seven hours when the norther ceased, and the returning sea floated us. This will give some idea of the force with which the water is driven across the keys and its power to cut channels. The greater part of the dry land (especially toward the western end of the archipelago) is found in its southern part. It may be this once formed a low, continuous ridge which acted as a dam to prevent the water of the Gulf from break- ing across into the strait. Thesea water, however, entered by seepage into the low, rocky land of the western part of the archipelago and by under- mining has broken it down into a confusing irregularity of outline. There are places in some of the lagoons where the water is six or seven feet deep showing undoubtedly that the rock has been removed by solution. Probably all of Ramrod and several other small keys have subsided slightly but enough to convert them into mangrove swamps. The dry-land vege- tation upon them has been destroyed, and almost THE FLORIDA KEYS 41 no traces of any of the large arboreal snails are to be found. Geologists believe that the islands west of Key West are of very recent origin, at least so far as their elevation above the sea is concerned. While those which lie between Key West and Boca Grande are of oolitic formation the Marquesas and Tortugas are composed of finely broken re- mains of various marine animals. At Tortugas extensive coral reefs have developed in the shal- lows along the edges of the land, the finest growth of this kind, perhaps, in the United States. The Marquesas, which consist of one large and several small islets, have an outline resembling a round- headed kite. The group is really an atoll, the outer keys forming a rim which encloses a shallow lagoon. It is not, however, a true coral atoll like those of the Pacific. The rock bed forming the foundation of the Marquesas was probably built up or elevated to very near the level of the sea. Wave action afterwards heaped up sand around the border and this now forms the dry land of the atoll. This sand covering has prevented or re- tarded dissolution of the foundation rock, but in the interior’ the less protected rock has been dis- 42 IN LOWER FLORIDA WILDS solved until a lagoon was formed. The Tortugas are believed to be an imperfect atoll, developed in much the same way as the Marquesas; so also is a minute island, ‘‘Key C,” lying to the west- ward of Key West. Boca Grande is also a pseudo atoll of the Marquesas type. In 1916 I visited the Marquesas for the purpose of finding a rare palm which had been discovered there several years before. As we drew near we sighted it among the thick scrub on the east side of the main island, and it proved at once to be a very distinct and handsome species. This is Thrinax keyensis of Professor Sargent only known from this group of islands and possibly from another small key of the lower chain. It has a stout, ashy gray stem, sometimes twenty-five feet high, raised on a conical base of matted roots. The shining rich green fan-shaped leaves have a brilliant silver color beneath, and are scattered for some distance along the trunk. It is really one of our most beautiful palms and quite distinct from any other in the State. Although unreported from any locality outside of this restricted area it is probable that it may yet be discovered in the Bahamas or West Indies. The islands on which THE FLORIDA KEYS 43 it has been found are so recent that it seems improbable a new species of palm could develop on them. With this we found also another, Thrinax wendlandiana, a native of Cuba but quite generally distributed over the Florida Keys and the south shore of the mainland. Aside from the common littoral vegetation, the mangrove, Avicennia, Laguncularia, and button- wood (which fringe all the keys) the only trees seen were the very common poison tree (Metopium metopium), Pithecolobium guadelupensis (also abundant in Lower Florida), and two stoppers,— Eugenia buxifolia and E. rhombea, the latter being confined in the United States to the Lower Keys. A few grasses and herbaceous plants were found and an intensive search brought to light but a single minute land snail, one of the Pupillide. The impression gained was that since the islet group formed there had been insufficient time for any considerable flora or fauna to develop. But there are still younger keys in this region. Sand Key, about six miles southwest of Key West is one of these—a mere rick of broken corals, shells, and sand, heaped up by the sea. It is an island of to-day. Not over an acre in extent it is used 44 IN LOWER FLORIDA WILDS as the site of a light house and weather station. On it are a few herbaceous plants—the first forms which nature establishes on newly made tropic land. These are a Tournfortia, a cousin of the cultivated heliotrope, a hoary leaved half shrub with white blossoms; Sesuvium portulacastrum, a creeper on the sands with thick leaves such as many of the shore plants have, and with it the widespread goat’s foot (Ibomea pes-capre). The latter has round, glossy leaves with a cleft at the apex, and large, handsome, purple flowers. With these are a few other salt loving plants. _ On this tiny islet were immense numbers of the least tern (Sterna antillarum), which, at the time of my last visit, were nesting, if simply laying eggs on the open sand could be so called. All of the sandy portion of the key was used for this purpose, and the only preparation for nesting consisted in moving the fragments of coral sufficiently to offer a smooth place on which to sit. I saw no birds actually sitting on eggs; probably they do this only at night leaving the hot sun to do the work of hatching. They flew around us angry and scream- ing when approached,—a wholly unnecessary demonstration since they are protected by law THE FLORIDA KEYS 45 from any interference during their nesting season. This graceful little bird was formerly abundant along the Atlantic coast but is now becoming quite scarce. We were told that this is their only breeding place on the Lower Keys. If, geologically speaking, Sand Key is an island born to-day there are others in the chain which are only just hatching. Western, Middle, and Eastern Sambo, lying east and south of Key West are such. So indeed is Looe Key, to the south of Ramrod Key, and also belonging to the outer reef. As yet these possess no vegetation whatever and the sea still breaks over them in heavy storms. At some distance out in the Hawk Channel in the vicinity of Key West is an incipient third reef lying within the outer one, and belonging to this are the Middle Ground, Washerwoman, Missis- sippi, and other shoals which are doubtless under- going the process of being formed into keys. This, then, is nature’s workshop for the making of islands, in which can be traced every process from the first coral polyp that attaches itself to the bottom and starts an incipient reef to the completed island raised well above the highest normal tide; or, from a tiny bar of mud or sand 46 IN LOWER FLORIDA WILDS deposited by some wayward ocean current to a great key covered with forests and other minor vegetation. Here countless bacteria change in- visible mineral elements in the sea water into impalpable mud which in turn hardens and be- comes rock. Here the mangroves toil to gather together and lay a foundation for what shall later be fertile soil. The sea in unceasing restless move- ment brings in material from near and far and heaps it up into shoals and future islands. But then with seeming inconsistency it turns and angrily smites and washes away these islands of its own making; it tears up the solid rock which it built along the shores, smashing it into frag- ments and scattering it far and wide. By its own chemical warfare it destroys the very limestone fortress it built so well. In seeming caprice the inconstant ocean creates the islands and devours them at the same time,— industriously building to-day—busily demolish- ing to-morrow. So delicately balanced are these opposing forces that the slightest change in con- ditions may cause the upbuilding to stop and the wrecking to begin. If the wind is gentle and sea smooth the constructive work progresses; if the THE FLORIDA KEYS 47 wind increases ever so little the waves tear down and destroy. Again, the very same forces may operate in exactly the opposite manner. But the work never stops,—constructive or destructive, it never ceases for one second. The flora of the entire chain of islands is inter- esting, notwithstanding the terrible devastation that man has wrought upon it. It is mostly derived from the American tropics, the majority of the plants being Cuban. Nearly all the higher land was once covered with forest which varied from low dense thorny scrub to tall closely set growth. The latter has doubtless been long established and a considerable amount of leaf mold has accumulated. Usually in such ham- mocks the ground is level and the rock is buried beneath a vegetable humus. In this spongy soil where one often sinks shoe deep little under- growth is seen. Some of the trees are of goodly girth and their straight trunks bear aloft dense heads of foliage. Such hammocks still exist on No Name, Pumpkin, Lignum-vite, Old Rhodes, Elliott’s, and on Key Largo.