Archipelago Area Research Articles

Epidemiology of anther-smut disease (Microbotryum violaceum) and numeric regulation of populations ofSilene dioica.

The interaction between the anther smutMicrobotryum violaceum and its hostSilene dioica was studied during 1985-1990 in 47 populations of different ages, sizes and densities, in an archipelago area in northern Sweden. The sizes of these populations had also been surveyed in the early 1970s. Our results indicate that establishment ofMicrobotryum violaceum is host-size and density dependent. Firstly, young populations ofSilene dioica that became diseased during the study were larger and tended to be more dense than young populations that remained healthy. Secondly, populations diseased in both 1985 and 1990 were found to be larger and tended to be more dense than populations healthy in both years. We were able to document that the pathogen actually failed to establish in two small young populations (diseased plants died shortly after they appeared) and did go extinct in one small old population. Disease incidences within populations did not show large fluctuations between years. The highest increases in disease incidence during the study were found in three relatively young populations that were disease-free at the start of the study. Older populations highly diseased at the start showed less of an increase. Our study indicates thatMicrobotryum violaceum acts as a regulatory factor influencing the rate of increase inSilene dioica populations, once they are sufficiently large to maintain the pathogen. Firstly, seedling density decreased with increased incidence of disease and a seed addition experiment indicated seed-limited recuritment in highly diseased populations. Secondly, those populations that reached very large sizes or densities were either healthy or had very low incidences, indicating the potential for populations that for one reason or another escape an epidemic. However, in the comparison of changes in population size over 16-18 years there was no simple correlation between expansion rate and disease incidence.

Production of the benthic amphipodsPontoporeia affinisandP. femoratain a Baltic archipelago

Abstract The production dynamics of Pontoporeia affinis Lindström and P. femorata Kröyer (Crustacea, Am-phipoda) were studied in 1980 near Tvärminne, SW coast of Finland. The study areas were located in the outer archipelago at depths of 21–25 and 26–30 m and in the sea zone at 46 m.p In P. affinis abundance declined from 12 000-17 000 ind. m-2 in May to 800–3000 ind. m-2 in November, but the maximum biomass of 5–8 g AFDM m-2 was attained in August. In the archipelago the daily production values were highest in June-July and biomass losses in July-August. In the sea zone production peaked in June but was considerable until autumn, and biomass losses increased toward autumn. Annual production to biomass ratios (P/B) declined from 2.9 to 1.3 with increasing depth. This decrease was most probably due to the lower temperature and food competition in the denser population of Ponloporeia at greater depths. The 0 + age group had the highest P/B ratio (4.8-3.4) and in the two archipelago areas about as high an annual production as the 1 + age group. In the sea zone production of the 1+ and 2+ age groups by far exceeded that of the 0+ age group. In P. femorata, present only in the sea zone, total abundance remained at a steady level of about 2500 ind. m-2 throughout the study period. The maximum biomass, 3 g AFDM m-2, was attained in September and was mainly composed of the 1 + and 2 + age groups. In all age groups maximum daily production values were attained in October-November. Daily biomass losses also peaked in the autumn. The annual P/B ratio for the entire population was 2.1, but the highest P/B ratio (3.4) was obtained for those young released in the spring.

Infection by Pathogens and Population Age of Host Plants

(1) The incidence of disease caused by host-specific systemic fungal pathogens was compared in populations of three host plants, Valeriana sambucifolia, Trientalis europaea and Silene dioica. (2) The study was conducted in an archipelago area in the Gulf of Bothnia, Sweden, subject to isostatic readjustment (land uplift). In this area primary succession is in strikingly different phases on different islands. The height above sea level of an island is correlated with island age and the time since it was first colonized by plants. Approximate ages of host-plant populations could thus be estimated. (3) In all three systems, disease incidence peaks during an early-intermediate phase of population development. In V. sambucifolia maximum disease (84%/,) occurs in forty to forty-five-year-old populations, in T. europaea in fifty to 100-year-old populations (-45%), and in S. dioica in fifty to 120-year-old populations (-600%0). Populations with an estimated age of greater than fifty years for V. sambucifolia, > 400 years for T. europaea and > 300 years for S. dioica show low disease incidences (< 10%). (4) A significant positive correlation between disease incidence and mean host population density was detected only for the Valeriana-Uromyces system, where the pathogen has an annual cycle, in contrast to the other two pathogens, which are perennial. (5) Three hypotheses could account for the observed population age-disease incidence pattern: (i) host population size and density effects, (ii) founder effects and selection for resistance, and (iii) changes in the environment during primary succession.

Mixed Carbonate and Volcaniclastic Slope Facies in a Middle to Upper Miocene Archipelago, Las Negras and Rodalquilar Areas, Southeastern Spain: ABSTRACT

The Las Negras and Rodalquilar areas contain excellent exposures of middle to upper Miocene carbonate and volcaniclastic deposits that fringe earlier formed Neogene volcanic substrates in an archipelago setting. The Miocene sedimentary sequence consists of three depositional sequences composed of reworked volcanic rocks and reef crest to distal slope strata that display 100-200 m of relief over 0.5-2.0 km. The entire sequence is truncated by a regional subaerial unconformity. The lower two depositional sequences are composed predominantly of shallow-dipping, normal marine, distal to proximal slope wackestones and packstones. The two sequences are separated by a megabreccia composed of Tarbellastreaea and Porites blocks and volcaniclastic sandstones and conglomerates. The reef blocks likely developed as upslope patch reefs, and, with the volcaniclastics, were eroded and transported via mass movements and tractive currents to a distal slope position. The upper (third) depositional sequence consists predominantly of foreslope strata of a Porites-dominated fringing reef complex. The base of this sequence is characterized by a megabreccia of Porites reef blocks, shallow-marine packstones, or volcaniclastic conglomerates. Five volcaniclastic wedges, interpreted as fan delta deposits, alternate with prograding carbonate foreslope deposits likely as a response to high frequency relative sea level fluctuations during a new sea levelmore » fall. The apparent correlatability of similar deposition sequences throughout the region indicates the importance of sequence development from allogenic processes, including glacio-eustatic sea level fluctuations and tectonism associated with the isolation of the Mediterranean Sea during the latest Miocene.« less

Fishing mortality rates of giant clams (Family Tridacnidae) from the Sulu Archipelago and Southern Palawan, Philippines

Average size frequency distributions of Tridacna squamosa, T. gigas, Hippopus hippopus and H. porcellanus harvested from the Sulu Archipelago and Southern Palawan areas from 1978–1985 were derived from export records and a warehouse inventory of giant clam shells. Average species mortality rates (Z) were estimated and were used to approximate average fishing mortality rates (F) over the period 1978–1985. Crude estimates of exploitation rates (F/Z) indicate that populations of these species are already overexploited. These findings have serious implications in view of the fact that the Sulu Archipelago and Southern Palawan are thought to be the last strongholds of giant clams in Philippine waters.

Precise location of unsurveyed seamounts in the Austral archipelago area using SEASAT data

Summary. SEASAT altimetric geoid data are used to detect uncharted seamounts in the Austral archipelago area. The various physical parameters which affect the geoid signature of a seamount are inspected to analyse their influence on the precision of the location. These parameters are the shape of the seamount, its density, the crustal model, the effective elastic thickness of the lithosphere and the distance between the seamount and sub-satellite tracks, respectively. The results of the tests performed on synthetic data as well as on charted structures show that when a seamount is detected on at least two neighbouring tracks, it is possible to locate it with good confidence and to give an estimation of its height. If the correct elastic thickness is assumed, the precision on the location is order 15 km.' Ten previously unsurveyed seamounts have been located in the Austral archipelago. It appears that they are emplaced along two well-defined azimuths (N 1 10°E and N 150'E) and that two parallel distinct volcanic chains form the Austral archipelago.

Precise location of unsurveyed seamounts in the Austral Archipelago area using SEASAT data : Baudry, N., M. Diament and Y. Albouy, 1987. Geophys. Jl R. astr. Soc., 89(3):869–888

Precise location of unsurveyed seamounts in the Austral Archipelago area using SEASAT data : Baudry, N., M. Diament and Y. Albouy, 1987. Geophys. Jl R. astr. Soc., 89(3):869–888

A new sediment trap system

A new sedment trap system intended for use in lakes and marine coastal and shelf areas is presented. The system is designed to (1) keep the sediment collection tubes in a steady vertical position, (2) avoid contamination of the samples by material detached from overhead rigging, (3) fachtate quick exchange of collection tubes at sea, and (4) provide duplicate samples. In situ experimental s tudes , SCUBA v T: trap retaining line; G : ground line; S: surface line. Line T is always taut whereas G and S are usually slack. ICT: inset collection tube; BB: buoyant body; F: frame; AS: attachment swivel. Dimensions of hollow frame: outer length 110 cm, outer width 30 cm, outer diameter of the tubes 5 cm, wall thickness 0.4 cm and marine coastal and shelf areas. Similar mooring arrangements are used to deploy current sensors (cf. Duxbury 1971). Study location and field test. The new sediment trap was tested in the Baltic Sea, near the Ask6 Laboratory about 65 km south of Stockholm, Sweden, in an archipelago area with negligible tide. The main test was carried out at 1.5 m depth in a narrow, 3.5 m deep sound, with relatively turbulent currents of up to 40 cm S-' . The degree of vertical stability of the collection tubes was recorded in situ by time-lapse filming. An 8 mm film camera was enclosed in a waterproof housing and mounted at the bottom of one of the collection tubes; the other tube was counterbalanced with gravel. The inner diameter of the tubes had to be 150 mm, to allow space for the camera. The entire trap was therefore scaled up according to the difference between the tubes in this test trap and the regular trap described above. At the top of the camera tube, 2 independent protractors were mounted, and readings recorded on film every 30 S. One protractor acted as a pendulum, recorhng the deviation from the vefical of the tube, the other was connected to an outside arm in order to give a relative reading of the current velocity. To relate the relative readings to actual current velocities a current meter was deployed close to the trap, integrating current velocities over 10 S. Readings were taken at intervals of 1 to 5 min. These current measurements were correlated to the corresponding protractor readings recorded on the film, using non-linear regression by SAS software (Allen Rey 1982). The regression equation (protractor reading = 0.203 current vel o ~ i t ~ ' . ~ ~ ~ , n = 26) was then used to estimate water currents every 30 S. Results. Despite highly variable water currents (5 to 40 cm S-') the collection tube of the new sediment trap Fig. 2. Predicted ambient water current velocities (above) and simultaneous recording, by time-lapse filming in situ. of the inclination from vertical of the collection tube of the EXPOSURE TIME (min) sediment trap (below) Larsson et al.: New sediment trap system 207 never deviated more than + 2.5 from a true vertical position (Fig. 2). Observations by water glass confirmed that the trap does not wobble and invariably maintains an alignment perpendicular to the current direction. In situ inspections of the regular trap by SCUBA diving at water depths down to 12 m in a coastal area support these observations. Not even when the diver rocked the trap frame did the collection tubes deviate noticeably from the vertical. Concluding remarks. The new sediment trap rnaintains satisfactory stabdity of the collection tubes and an alignment perpendicular to the current direction at highly variable current velocities (up to at least 40cm S-'). The buoyancy of the trap permits a noninterfering mooring arrangement. The new trap has functioned reliably for more than 4 yr in a coastal area of the Baltic Sea. Acknowledgements. Ragnar Elmgren and Jiirg Bloesch commented on the manuscript, Sture Hansson assisted in the divmg, Leif Lundgren drew the figures and Maureen Moir typed and corrected the language. This work was supported by the National Swedish Environment Protection Board and the Swedish Natural Science Research Council.

Partitioning of nutrient uptake between annual and perennial seaweeds in a Baltic archipelago area

Partitioning of nutrient uptake between annual and perennial seaweeds in a Baltic archipelago area

Structural evolution of Svecokarelian migmatites, southern Finland: a study of Proterozoic crustal development

ABSTRACTSvecokarelian migmatites in the Jussarö area of the southern Finnish archipelago comprise tonalitic gneiss, amphibolite, metagabbro, microgranite, the metamorphosed derivatives of sediments, including carbonates and graded argillites, together with later-emplaced potassic granite, and basic and acidic pegmatites. The rock assemblage shows evidence of repeated deformation; a succession of 15 sets of folds (and fold-related structures) is identified and documented. There are two sets of early intraf oliai isoclinal folds (Faa and Fab), isoclinal folds (Fbr), recumbent folds (Fx), upright open folds (Fy), tight upright folds (Fbb), two sets of asymmetrical folds (Fc and Fd), ‘scar’ folds (Fb1, Fcb Fd1), slip folds Fb, conjugate shear folds (Fe), angular folds (Fn), open warps (Fw) and tight ductile shears (Fds). From isotopie evidence reported elsewhere, the evolution of this crustal segment of the Svecokarelides is known to have spread over a period of approximately 200 m.y. from c. 1900 m.y. to c. 1700 m.y.

Occurrence of methyl mercury in pike and Baltic herring from the Turku archipelago

The content of methyl mercury in pike and Baltic herring from seven different areas of the Turku archipelago (the southwestern coast of Finland) was studied. Pike muscle contained on average 0·27 mg Hg/kg on a fresh tissue basis. However, the concentrations of methyl mercury varied considerably between individuals from the same fish population, e.g. from 0·06 to 1·3 mg/kg, depending on the weight (and age) of fish. The values for methyl mercury in standardised weight (1 kg) pikes were on a natural level (varying between 0·19 to 0·25 mg/kg) in all other areas of the archipelago, except in the area near the city of Turku, where slight contamination (0·39 mg/kg) was noticed. In different tissues of pike the level of methyl mercury decreased in the following order: muscle tissue > liver ≥ kidney ⪢ gonads. Baltic herring muscle contained on average 0·09 mg Hg/kg, the value being only one-third of that of pike muscle.

Coral-Reef Asteroids of Guam

Most coral-reef asteroids of Guam, at least 24 species in total, represent those which are widely distributed in the IndoWest Pacific. The diversity of asteroid fauna in Micronesia and its surrounding region follows a general trend of a faunal center in the rich Indo-Malayan Archipelago area with the number of species diminishing eastward in the scattered and remote oceanic islands. Larval development in many common reef asteroids is oriented toward dispersion by producing planktotrophic and surface-floating larvae which stay in the pelagic environment for three weeks or longer. The major oceanic surface currents flow westward, driven by steady trade winds in the area surrounding Guam and most of the Micronesian Islands. It is argued that local recruitment of asteroid populations might be hazardous under such circumstances where coastal water masses would hardly conserve larval populations inshore. Juvenile populations of reef asteroids have been rarely located in the field, in spite of conspicuous adult populations. Feeding habits, life histories, and other aspects of natural histories of reef asteroids are discussed. THE CURRENT PROBLEM of Acanthaster planci infestations on reef-building corals has called attention to the fact that little knowledge concerning the biology and ecology of coral reefs and their associated organisms has been accumulated to date. Although there are reports on systematic and zoogeographical studies of coral-reef asteroids and other echinoderms in the tropical Indo-West Pacific (see recent monograph by Clark and Rowe 1971), little is known about behavioral aspects of population recruitment or about feeding, growth, predation, and life history. The problem of Acanthaster infestations is essentially a matter of population dynamics. An understanding of the mode of population recruitment of the starfish to the coral-reef environments of oceanic islands is vitally important in evaluating the processes maintaining asteroid populations. The confusion among the many hypotheses which have been developed to explain the causes of Acanthaster infestations seems to derive for the most part from lack of knowledge concerning the manner and processes of recruitment to the coral reefs. Thus there are two extreme predictions concerning the infestation: one expects expanding infestations to occur as long as human interference with nature exists (Chesher 1969), and the other suggests that present infestations are episodic phenomena (Walsh et al. 1971). Although arguments about infestations are concentrated only on Acanthaster planci, the existence of many other conspicuous coral-reef asteroids must be considered. In spite of the great diversity of adult structure, habitat, behavior, and population densities, many common asteroids produce larvae with similar structure and behavior (Yamaguchi 1973a). This situation suggests that environmental pressure to reduce larval populations may work in a similar manner among many species, resulting in stereotyped larval forms. The island of Guam is located in the trade wind zone where steady, continuous winds produce surface currents drifting in one direction for long periods of time over much of the year. Most asteroid larvae, as well as larvae of other shallow-water inhabitants, may be transported by the currents away from the island for a great distance and would be most unlikely to be able to recruit to the mother populations. Many asteroids have a threeto fourweek larval life span as plankton. This period is long enough for their wide dispersion and transportation, for example, over the distance from Guam to the Philippines, if given a current velocity of one and a half knots. Almost nothing is known about water movement in the open ocean nor in the areas near the islands, except for some crude data on prevailing current such as the North Equatorial Current. Eddy formation and movement multiplies problems of understanding larval dispersion. It is difficult to discuss the mode of recruitment and colonization of coastal animals on coral reefs when we lack reliable information on water movement and its effect on the breeding behavior of these animals and on their larval ecology. 1 Supported in part by the Government of Guam Acanthaster research appropriation and NSF grant GA39948. Contribution No. 54, University of Guam Marine Laboratory. 12 BIOTROPICA 7(1): 12-23 1975 This content downloaded from 157.55.39.159 on Sun, 18 Sep 2016 05:49:46 UTC All use subject to http://about.jstor.org/terms GEOGRAPHICAL DISTRIBUTION OF CORAL-REEF ASTEROIDS IN MICRONESIA AND SURROUNDING

Occurrence of DDT and PCB compounds in Baltic herring and pike from the Turku archipelago

The contamination of Baltic herring and pike from six different areas of the Turku archipelago (the southwestern coast of Finland) with DDT and its metabolites DDE and DDD, and PCBs (polychlorinated biphenyls) was studied. Herring muscle contained on average 0·38 ppm Σ DDT and 0·31 ppm PCBs on a fresh tissue basis. However, the values obtained for individual fish specimens showed large variations, depending mainly on the differences in the fat content of the fish. The range of DDT and PCB concentrations in herring from the Turku archipelago was similar to that found in herring from the Gulf of Bothnia. Pike muscle contained on average only 0·04 ppm DDT compounds and 0·05 ppm PCBs on a fresh weight basis. The results show local differences in the residue concentration of the fish. The chlorinated hydrocarbons were found to accumulate in the liver and ovary of the pike and, to a lesser degree, in the testis and kidney. In the ovary fat the Σ DDT concentration rose to 100 ppm and that of PCBs to 190 ppm.

Geology of Offshore Areas of The Canadian Arctic Islands Based On Geophysical Data

Abstract Surface geologic exposures in the Arctic Islands are excellent, as is the case in most of the world's deserts. The sparse subsurface information from bore holes is limited to only a few islands. The geology of the inter-island areas is much more speculative. Preliminary interpretations based on erosion and isostatic readjustments after the melting of the continental ice sheet may have to be revised after a review of the geophysical data which are now becoming available. Hypotheses concerning block faulting with horst and graben development represent a conservative approach, whereas the consideration of rift and drift hypotheses gains popularity. Recently obtained reconnaissance data indicate the possibility that a distinct geologic section exists offshore compared to the onshore boundaries. This conclusion is based on regional geophysical data obtained by government and industry. Magnetic and gravity surveys coyer much of the Arctic Archipelago Seismic profiles in marine areas of sourthern Arctic Islands indicate a wide range of large structures, and refraction probes are useful in defining the velocity, and thus the possible geologic age of these sediments. Introduction THE CANADIAN ARCTIC ISLANDS have attracted the venturous for more than 300 years and even in our own time we have seen men in quest of a northwest passage. Continental borderlands have become major oil search areas throughout the world since the development of a concept that the offshore is more than just an extension of onshore geology. Continental shelves often present a whole new and very thick sedimentary section. Integration of the large volume of data compiled by the Canadian Government with newly acquired data from industry stimulates renewed interest in the offshore and inter-island areas of the Arctic Archipelago. The Canadian Arctic Islands are on the north flank of the North American craton. Major extensions of the Precambrian basement are noted, such as the Minto Arch in the southwest and the Boothia Uplift on the south, as seen in Figure 1. Hachured areas indicate Paleozoic sediments comprising the stable shelf and geosynclinal trough of the Franklinian geosyncline. The thickest portion of this earlr depositional area along the north edge of the Paleozoic outcrop has been compressed and faulted by late Paleozoic deformation. Most of the exposed area of the Franklinian geosyncline (Kerr, 1967a) is of miogeosynclinal suite. Eugeosynclinal sediments are exposed in Northern Ellesmere Island (Trettin, 1967). The central portion of the Arctic Islands has been called the Sverdrup Basin. This depositional basin is about 700 miles long and 250 miles wide, and is composed of Mesozoic and Cenozoic sedimentary sequences. The Paleozoic Franklinian geosyncline accumulated about 40,000 feet of carbonates, shales and some sands. An additional 40,000 feet of shales and sands are present in the Mesozoic Sverdrup Basin. Excellent geologic exposures facilitated aerial photographic mapping of the islands, and aerial field mapping was carried on during the short summer seasons. Aeromagnetic gravity and seismic work followed on shore and, although logistics are difficult good results were generally obtained.

ECOLOGY AND POPULATIONS

Alm, B., Myhrberg, H., Nyholm, E., &amp; Svensson, S. 1966. Densities of birds in alpine heaths.Ellinthorpe‐White, S. L. 1966. Winter populations and movements of Wildfowl at Falsterbo Peninsula:January to March 1964.Ernholdt, T. 1966. (The occurrence of the Golden Oriole (Oriolus oriolus) in Sweden 1944–1964.)Grant, P. R. 1966. The coexistence of two wren species of the genus Thryothorus.Grenquist, P. 1966. A summary of changes in abundance of Finnish duck and sea‐bird populations in four southern archipelago areas 1950–1962 and some causes influencing them.Lindberg, P. 1966. (Irruption of the Pygmy Owl (Gluucidium passrinum) into Southern Scandinavia, 1963–64.)Olney, P. J. S. 1966. Berries and birds.Pitman, C. S. R. 1962. Waterfowl predation in Canada by the Northern Pike (or Jackfish) Esox luciusPynnonen, A. 1963. (Variations in the abundance of the Hazel Grouse (Tetrastes bonusia).)Uusvaara, O. 1963. (The structure of the habitats of the Hazel Grouse (Tetrustes bonasia).)

The Lady and the Banyan Tree: Civil-Law Change in Indonesia

In 1960 the blindfolded lady with scales was replaced as Indonesia's symbol of justice by a stylized banyan tree, inscribed with the Javanese word Pengajoman-protection and succor.' It was generally agreed that the new symbolism struck a true note, despite cynical comment in private on the real deterioration of justice since the end of the revolution (1945-1950). The satisfaction may have been mainly esthetic, but substituting the Asian banyan tree for the European lady did reflect the concern of Indonesian leaders to return to their own traditions. It also represented a quickening of the process of transformation of the heritage of Dutch colonial law into Indonesian law. This was an awesome heritage, born of a plural legal order almost as intricate as the colonial society which it served. Colonial public policy in the Netherlands-Indies recognized the existence of distinct population groups: Europeans, Indonesians, Chinese, and other 'foreign orientals,' mostly Arabs. There were two separate secular judicial structures, one for Indonesians and one for Europeans. All population groups were subject to the same criminal code, promulgated in 1914, but according to two different procedural codes. In civil matters Indonesians followed the adat (customary) law, which itself varied from area to area of the great archipelago. European civil law was provided in copies of the originally Napoleonic Dutch civil and commercial codes. In the criminal law Chinese and Arabs were considered to be assimilated to Indonesians, in the commercial law to Europeans,

ISOLATION, ENDEMISM, AND MULTIPLICATION OF SPECIES IN THE DARWIN FINCHES

In this paper we use multiple-regression analysis to consider the general evolutionary problem of the relative importance of the various factors governing the proliferation of related subspecies or species on member islands of an archipelago. From this quantitative analysis of the relation of isolation to endemism and sympatry' in the Darwin finches, deductions are made concerning (i) the location within the Galapagos Archipelago of insular sites of origin of the species and (ii) whether or. not these sites are also the ones where the remarkable, external morphological divergences characteristic of the group occurred. Together these considerations constitute a reinvestigation of factors underlying the processes of species multiplication and differentiation within an archipelago, and it is hoped that this will encourage students of other groups of organisms to make comparable comparisons and determine if our generalizations are universally applicable. For the Darwin finches (Geospizinae), which have undergone a moderate, adaptive radiation2 within the strongly isolated complex of the Galapagos Islands, we have found it useful to ask the question: Why, in this bird group of restricted distribution, is there a tendency for many species and few endemic subspecies to occur on some islands, and for few species but more endemics to occur on other islands (see fig. 1)? Explanation of the negative relation (correlation coefficient or r =-0.60) between insular numbers of species and insular numbers of endemic subspecies relates to the evolutionary problem cited. Under various guises, the problem has been taken up by others, with Ridgeway (1896), Swarth (1931, 1934), Lack (1947), and Bowman (1961) being major references to the topic. We seek in the present study of the Darwin finches an evaluation that is more statistically oriented than is usual for such problems (cf., however, Kramer and Mertens, 1938). Our determination of partialregression coefficients by the method of least squares involves estimation of the partial influences on total insular numbers of either species or endemic subspecies of the following four factors: insular area; insular numbers of land plant species; insular isolation as measured by distance from nearest island; and insular isolation as measured by distance from Indefatigable Island located in the central archipelago area.

Data for the investigation of the seismic sea-waves in the Eastern Mediterranean

This paper is condensed from data compiled for the investigation of the seismic sea-waves in the Eastern Mediterranean (31-44° N to 18-36° E). It contains the results of the first stage of the study which, in its greater part, consists of a list of waves about which we found useful data for a correlation between the seismicity and the sea-floor morphology of the region. It is shown that the Eastern Mediterranean is often subject to seismic sea-waves, whose intensity varies from “light” to “strong.” Waves of higher intensities are very rare and strongly local. There are good reasons to believe that certain areas of the region give rise to waves, whose origin must be sought in submarine landslides. For certain central areas of the Grecian Archipelago, crustal tilting rather than tectonic deformations of the sea-floor seems to be a very probable cause for some of the waves observed. Finally, a brief survey of some early ideas about the mechanism of seismic sea-waves is included.

Two New Digenetic Trematodes from Marine Fishes of Puget Sound, Washington

The host fishes were collected during the months of July and August 1957, in the marine waters of the area of the San Juan Archipelago as a portion of a research program which was carried out by the author at the Friday Harbor Laboratories of the University of Washington. Stafford established the genus Fellodistomum in 1904, using Distomum incisum Rudolphi, 1809, as the type species. The description was expanded and clarified by Nicoll in 1909, and verified by Miller in 1941 after a study of Stafford's report and trematode collection.

Variation and speciation in the Australian Campephagidae (Passeres).

The present paper reviews the taxononly of and discusses speciation in the Australian members of the family Campephagidae (cuckoo-shrikes and trillers), embracing the genera Pteropodocys Gould, Coracina Vieillot, Edolisoma Pucheran, and Lalage Boie. Isolates are few in number on the continent. This presumably results from most species having rather generalized habitat requirements, continuous ranges, being large and mobile, and undertaking seasonal wanderings. Four of the species extend widely through the tropical islands to the north. An archipelago area of about the same size as Australia provides an interesting contrast with the continent, there being some 35 morphologically differentiated isolates as against 7-10 on the latter. Tropical islands (with a constant supply of food all the year round ?) apparently favour the development of the sedentary way of life and isolation, just as the drier conditions of Australia favour nomadism and the maintenance of breeding continuity. The bulk of the insular forms, however, are small populations with restricted ranges, and must lack the adaptive gene pool of their continental congeners. Because of this their evolutionary future is presumably limited. Attention is drawn to an interesting comparison between two species that undertake equally extensive seasonal movements. One, Lalage sueurii, does not vary at all geographically, but the second, Coracina novaehollandiae, has marked clinal variation and two, possibly three, isolates. The reasons for this are discussed. The point is made that seasonal movements per se may not prohibit the development of geographic variation but that this depends on the nature of the movements.