COMPARISON OF THE STRUCTURE OF THE PALLIAL TENTACLES OF SEVEN SPECIES OF SOUTH AFRICAN PATELLID LIMPET

The ultrastructure of the pallial tentacles of seven speciesof patellid limpet is described. The tip of most of the tentaclesexamined bears a crown of long cilia, whereas the shaft of thetentacles has small tufts (5–10 µm diameter) ofshorter cilia. Sections through the ciliated tufts show themto be composed of several cells, each bearing cilia. The ciliacontain 5–7 central microtubules and therefore do nothave the conventional 9 + 2 arrangement of microtubules. Nerveprocesses run from the base of each ciliated cell to a nervebundle in the centre of the tentacle, suggesting a sensory function.Estimates of densities of ciliated tufts suggest that the territoriallimpets (Patella cochlear and P. longicosta) have the greaternumber of tufts. Electron dense plate-like structures are foundin the centre of the pallial tentacles of Patella cochlear,P. longicosta, P. granularis, P. barbara and Helcion pruinosus.Each plate is about 0.2 µm wide and is surrounded by adouble membrane. It is suggested that these may play a rolein scattering or reflecting light and thus form part of thedermal light sensing ability of these animals. (Received 26 January 1987;     

EFFECTS OF WOUND HEALING ON ZINC DISTRIBUTION AND ALKALINE PHOSPHATASE ACTIVITY OF HELIX ASPERSA (GASTROPODA: PULMONATA)

Helix aspersa were loaded with ⁶⁵zinc and after 2 and 5 daysstarvation there was no significant reduction in the zinc concentrationof the digestive gland and shell. Wounding of the optic tentacle,foot tissue and partial shell removal of H. aspersa resultedin deposition of ⁶⁵zinc in the wound area. Alkaline phosphataseshowed no increase in concentration at the sites of wounding. (Received 15 October 1985;     

Studies on the Growth in Culture of Plant Cells: IV. THE INITIATION OF DIVISION IN SUSPENSIONS OF STATIONARY-PHASE CELLS OF ACER PSEUDOPLATANUS L.

Techniques are described whereby a culture medium can be ‘conditioned‘by separation from a dense cell suspension either by a sinteror by a dialysis membrane. The enhanced growth-promoting activityof the conditioned, as compared with a new medium, is revealedby using a low density of cells (15 x 10³ or less cells perml) to initiate the test cultures from a stationary-phase suspension.The optimum pH of the conditioned medium is c6.4. To obtaina conditioned medium of high activity it is necessary to usean appropriate volume ratio of culture medium to conditioningcell suspension and to limit the conditioning period. Conditioningof the culture medium reduces by a factor of 10 (i.e. down toc. 1000 cells per ml) the minimum effective cell density neededfor self-sustaining growth. There therefore exists a population-dependentrequirement which is not met by the conditioned medium as nowprepared. The retention of the activity of the conditioned mediumin various situations has been studied as a preliminary to workon the chemical basis of conditioning.     

THE DIET, PREY SIZE AND CONSUMPTION OF PHILINE ORIENTALIS (OPISTHOBRANCHIA: PHILINIDAE) IN HONG KONG

Philine orientalis occurs on Hong Kong's beaches for {smalltilde}2 months each year, in May and June when it breeds, laysegg capsules and dies. It is believed to have a life span ofone year. Hoi Sing Wan, a sandy beach in the New Territoriesof Hong Kong is dominated at lower levels by the venerid bivalveTapes philippinarum, the population of which in May and June,following spring recruitment, mostly comprises juveniles. P.orientalis, occurring at a density of {small tilde} 1.m^–2,feeds voraciously upon these juveniles consuming, in laboratoryexperiments, a mean of 25.day^–1. At Hoi Sing Wan, P. orientalisappears to be highly prey specific. It is, however, known tofeed on other prey items and probably has a catholic diet, duringits annual migration from deeper to shallower sediments, accordingto the prevailing fauna. In terms of wet weight, P. orientalis consumes a mean of {smalltilde}4.4% (2.2–6.7%) of its body weight day^–1.In terms of dry weight, however, this figure increases to amean of 35.5% and one figure of 208% has been recorded. Althoughthis is because of the large body fluid content of this, essentiallyshell-less, gastropod, using a hydrostatic skeleton to achieveburrowing, such figures further attest to the voracity of thebreeding adults. This study joins others in questioning ourpresent understanding of the scale of energy budgets on suchshores, i.e., are our estimates of loss to predation grosslyunderestimated? ^*Present address: Department of Biology, Baptist College, WaterlooRoad, Kowloon, Hong Kong. (Received 20 May 1989; accepted 3 July 1989)     

Feeding, prey selection and prey encounter mechanisms in the heterotrophic dinoflagellate Noctiluca scintillans

The heterotrophic dinoflagellate Noctiluca scintillans has anegligible swimming ability and feeds predominantly on immobileprey. How, then, does it encounter prey? Noctiluca scintillansis positively buoyant and, therefore, we hypothesized that itintercepts prey particles during ascent and/or that microscaleshear brings it into contact with prey. Noctiluca scintillanshas a specific carbon content 1–2 orders of magnitudeless than that typical for protists and, thus, an inflated volume.It also has a density slightly less than that of the ambientwater and therefore ascends at high velocities (-1 m h^–1).In stagnant water, clearance rates of latex spheres (5–80µm) increased approximately with prey particle size squared.This scaling is consistent with N.scintillans being an interceptionfeeder. However, absolute clearance rates were substantiallylower than those predicted by modeling N.scintillans both asa spherical and as a cylindrical collector. The latter modelassumes that prey particles are collected on the string of mucusthat may form at the tip of the tentacle. Feeding, growth andprey selection experiments all demonstrated that diatoms arecleared at substantially higher rates than latex beads and otherphytoplankters, particularly dinoflagellates. We propose thatdiatoms stick more efficiently than latex beads to the mucusof N.scintillans and that dinoflagellates reduce fatal contactbehaviorally. We conclude that N.scintillans is an interceptionfeeder and that the high ascent velocity accounts for encounterswith prey. However, the flow field around the cell-mucus complexis too complicated to be described accurately by simple geometricmodels. Fluid shear (0.7–1.8 s^–1 had a negativeimpact on feeding rates, which were much less than predictedby models. Noctiluca scintillans can survive starvation forlong periods (>3 weeks), it can grow at low concentrationsof prey (-15 µg C l^–1), but growth saturates onlyat very high prey concentrations of 500–1000 µgC l^–1 or more. We demonstrate how the functional biologyof N.scintillans is consistent with its spatial and seasonaldistribution, which is characterized by persistence in the plankton,blooms in association with high concentrations of diatoms, andsurface accumulation during quiescent periods or exponentialdecline in abundance with depth during periods of turbulentmixing.     

THE ULTRASTRUCTURE OF CILIATED CELLS FROM THE SIPHON OF SOLEN CAPENSIS (MOLLUSCA, BIVALVIA)

The structure of ciliated cells from the siphon of Solen capensishas been studied by both scanning and transmission electronmicroscopy. Two types of ciliated cell, based on the numberand length of cilia have been described which resemble thosedescribed in Donax. Type I is characterized by having 26–57({macron}= 43, n = 50) cilia which are 2.5 µm in length;Type II has fewer cilia (5–10; {macron}= 7) which are5 µn long. Both are primary receptors. Estimations ofabundance show that receptors are most numerous on the tipsof the siphon tentacles (8.8 x 10³/mm²). (Received 15 January 1985;     

Bloom of Emiliania huxleyi (Prymnesiophyceae) in the western South Atlantic Ocean

A monospecific bloom of the coccolithophorid Emiliania huxleyi(Lohmann) Hay & Mohler (Prymnesiophyceae) was detected offRio de La Plata at 36°S and 54°W in November 1989. Thecell densities observed were up to 6x10⁵ cells I^–1. Thisis the first record of a bloom of E.huxleyi in the area.     

The Potential of Two Perennial C4 Grasses and a Perennial C4 Sedge as Ligno-cellulosic Fuel Crops in N.W. Europe. Crop Establishment and Yields in E. England

Three perennial C₄ rhizomatous species, Cyperus longus L., Spartinacynosuroides and Spartina pectinata Link, were examined as potentialrenewable energy crops. These species are unusual among C₄ plantsin showing natural distributions which extend into cool temperateregions. This study examined whether these species could beestablished in the cool temperate climate of eastern Englandand whether they could consistently attain the relatively highdry matter yields associated with C₄ plants of warmer regions.Clonally produced material was planted in 1986, on two siteswith contrasting soil types in Essex, eastern England. Plantingwas within a randomized-block design incorporating replicatedplots of each species, both with and without fertilizer. Survivorshipand stem demography were monitored at monthly intervals from1986 to Jun. 1989 for stem recruitment and to Dec. 1991 forstem density. Yields were determined from 1987 (the year followingestablishment) to 1993. Survivorship of the planted propagules over the first 12 monthswas 92% for S. pectinata , 96% for S. cynosuroides and 100%for C. longus. Recruitment of new stems peaked in Apr. of mostyears, although a significant number of new stems appeared asearly as Feb. Stem death peaked in Sep. or early Oct. and allabove-ground stems had died by mid-Nov. Stem density trendsindicated that 2-4 years were required to reach a steady-statedensity, depending upon species. The stem density of the twoSpartina species had reached more than 1000 m^-2 in 1989 althoughthat of S. pectinata fluctuated considerably in the subsequentyears. C. longus stem density rose to approx. 600 m^-2 by 1988and did not change significantly in the subsequent years. In the 6 years following establishment, annual yields averagedacross all fertilizer treatments and both sites were 1·0,1·1 and 1·3 kg m^-2 for C. longus, S. cynosuroidesand S. pectinata, respectively. The average annual yield ofall three species at the site with the heavier soil was 1·3kg m^-2. This was significantly greater than the 1·0 kgm^-2 on the lighter soil. Nitrogen addition did not significantlyincrease yield. Even in the absence of any nitrogen addition,the annual yield of S. pectinata averaged 1·2 kg m^-2over the 6 years, with no evidence of any decline with the increasingage of the stands.Copyright 1995, 1999 Academic Press Cyperus longus, Spartina cynosuroides, Spartina pectinata, energy crop, dry matter yield     

THE LIFE CYCLE, POPULATION DYNAMICS, GROWTH AND SECONDARY PRODUCTION OF THE SNAIL BRADYBAENA FRUTICUM (MULLER, 1774) (GASTROPODA PULMONATA) IN NORTHERN GREECE

The life cycle, population dynamics, growth and secondary productionof the pulmonate land snail Bradybaena fruticum were studiedin northern Greece. The demographic analysis of the populationsof B. fruticum revealed that a) two cohorts exist in the fieldthroughout the year b) the reproductive period started in thebeginning of summer and c) growth was increased during springand autumn. According to von Bertallanffy' method B. fruticum needs 5 yearsto attain its maximum size in the field of 25.40 mm. Mortalityrate increases and life expectancy decreases with increasingage. Net reproductive rate (Ro) was equal to 3. 15 and per capitarate of increase (r^c) was equal to 1. Annual secondary production, calculated by Hynes' size frequencymethod, revealed a mean annual density of 5.9 individuals/m²,a mean standing crop (B) of 8.09 g/m²/year and an annual production(P) of 1.92 ± 0.11g/m²/year. Annual turnover ratio (P/B)was equal to 2.37. (Received 25 May 1989; accepted 17 March 1989)     

Proton Pumping Pyrophosphatase in a High Density Fraction of Radish Microsomes

Radish (Raphanus sativus L.) microsomal vesicles show a vanadate-?nd nitrate-insensitive, and imidodiphosphate-sensitive electrogenictransport of protons dependent upon addition of inorganic pyrophosphate(PP) or ADP. The activity is detectable in preparations from24 h-old seedlings and increases about 3 fold in vesicles from72 h-old seedlings. The ADP-dependent proton uptake, being preventedby inorganic pyrophosphatase, used as a PP scavenging system,can be ascribed to enzymes utilizing ADP and producing PP whichappears the only substrate for the proton pumping PPase. TheH⁺-PPase has a K_m of ca. 10 µM for the translocating functionand 20 µM for the hydrolytic activity. It has a pH optimumnear to 7.0 and is stimulated by certain monovalent cations(K⁺, Rb⁺ and Cs⁺). The majority of this activity is associatedwith a high density (35–45% sucrose interface) fractionwhich is enriched for vanadate-sensitive, nitrate-insensitiveATPase activity. (Received September 11, 1989; Accepted December 22, 1989)     

Increased Resistance to Acriflavine by Amplification of the acrA Gene of Escherichia coli K-12

The wild-type acrA⁺ gene of Escherichia coli K-12, cloned intoplasmid pAF1, was expressed as resistance to acriflavine (AF)in AF-sensitive acrA mutant cells (N43). When acrA⁺ genes wereamplified by treatment of cultures with chloramphenicol (50µg/ml), cells expressed much higher resistance to AF thanthat of the wild-type strain (N90). (Received November 22, 1989; Accepted July 7, 1990)     

A QUANTITATIVE STUDY OF A CERASTODERMA -- NEPHTHYS COMMUNITY IN THE LIMFJORD, DENMARK, WITH SPECIAL REFERENCE TO PRODUCTION OF CERASTODERMA EDULE

Cerastoderma edule is the dominant member of a non-random Cerastoderma—Nephthyscommunity, occupying a physically, homogeneous, submerged sandbankin the Limfjord, Denmark. C. edule is patchily distributed withinthis community, growth rates showing a clear density-dependence.Individual production is about 35%lower in high density patchesthan outside them; at low density annual individual flesh dryweight increment is 295 mg. Seasonal variation in water, ash,lipid, protein and glycogen contents is studied, and a sizedependent(= density-dependent) relationship is shown to exist for someparameters. Population production, estimated by a new graphicalmethod, and taking into account gametic and shell protein production,attains 150 g dry flesh weight, m^–2.yr^–1 at meanpopulation density rising to 250 g dry flesh weight. m^–2.yr^–1in the high density patches. ¹Present address: Institut für Physiologische Chemie, Abt.Zellbiochemie, Universitat Hamburg, Martinistrasse 52, 2000Hamburg 20 (Received 10 March 1980;     

Ultrastructural Localization of Ions: IV. LOCALIZATION OF CHLORIDE AND BROMIDE IN NITELLA TRANSLUCENS AND X-RAY ENERGY SPECTROSCOPY OF SILVER PRECIPITATION PRODUCTS

The cytoplasmic distribution of Cl^– in Nitella translucenswas assessed by means of two contrasting approaches. The firstinvolved the histochemical precipitation of Cl^– with Ag⁺followed by X-ray analytical verification of the silver precipitationproducts, and the second, quench-freezing of whole Nitella cellsfollowed by freeze-substitution in the presence of silver underanhydrous conditions. Both methods produced identical evidencefor Cl^– distribution, showing that a large proportionof the Cl^– is present in the stationary cortical gel layerwhich includes the chloroplasts. However, the chloroplasts appearedto be low in Cl^– content while the bulk of the Cl^–appeared to be situated between the chloroplasts and plasmalemma. Experiments were carried out in other to detect the pathwayof the ‘fast component’ of halide ion transfer tothe vacuole. Br^– was supplied for various time intervalsto low Cl^– Nitella cells, followed by attempts to differentiatebetween AgCl and AgBr deposits. Solutions of various strengthof NH₄OH or ammonium carbonate were used to remove AgCl (butnot AgBr) deposits by formation of a Ag(NH₃)₂⁺ complex. AlthoughX-ray analytical verification showed that the method had somepotential usefulness it could not be carried out successfullybecause of loss of structural detail caused by NH⁺₄. The distribution and density of deposits near the plasmalemmasuggested the occurrence of a process in which cytoplasmic loadingis achieved by a sequential rupture and repair of the plasmalemmamembrane. Vesicles and reticulate structures in the streamingcytoplasmic phase generally showed very little deposit, butthese structures, together with the tonoplast, became greatlyenriched with deposits when cells had been given a brief exposers(3 min) to a Cl^– or Br^– solution. These rapid changesmay possibly be related to the ‘fast component’of halide ion transfer to the vacuole.     

FACTORS CONTRIBUTING TO SPATIAL HETEROGENEITY IN THE ABUNDANCE OF THE COMMON PERIWINKLE LITTORINA LITTOREA (L.)

Although Littorina littorea (L.) exhibits a relatively consistentpattern of vertical distribution throughout the North Atlantic,ranging from the mid-intertidal to the shallow subtidal zone,its horizontal distribution and abundance are highly variable.In this study, we first described the snail's horizontal distributionpatterns on Appledore Island, ME, USA and then asked whetherwave exposure, rugosity, predator density (e.g. Carcinus maenasand Cancer borealis), the percentage of the substrate coveredby Ascophyllum nodosum, Chondrus crispus, Polysiphonia spp.,and ephemeral green algae, or the percentage of uncovered substrate(bare rock) were correlated with L. littorea abundance in theintertidal zone (0.6 to 0.0 m relative to Mean Lower LowWater [MLLW]) and the shallow subtidal zone (–1.5 to –3.0 mMLLW) at nine study sites. Intertidal densities of L. littoreawere highly variable across sites, ranging from 0 to >600 m^–2.In this zone, L. littorea density showed a significant positivecorrelation with rugosity and percentage of bare rock. Densitieswere very low in the subtidal zone (range: 0–19 m^–2)and varied little among sites. Exploratory multiple regressionanalysis suggested that L. littorea density was positively correlatedwith the density of C. maenas in the shallow subtidal zone.Additionally, snails in the subtidal zone had thicker shellsthan snails of the same size in the intertidal zone. Our resultssuggest that structural elements of the habitat, such as rugosityand percentage of uncovered substrate, are among the most importantpredictors of L. littorea abundance on moderately protected,rocky intertidal shores. (Received 9 February 2005; accepted 10 August 2005)     

Autoecology and some life history stages of Dinophysis acuta Ehrenberg

A persistent and unusual bloom of Dinophysic acuta Ehrenbergin the RIas Bajas (Northwest Spain) from early July to mid-November1989, was associated with a diarshetic shellfish poisoning (DSP)outbreak that prevented mussel extraction in some areas fromearly August to mid-December. Integrated samples (0–5,5–10 and 10–15 m) were taken once or twice a weekat six stations. Maximum numbers of D.acuta (up to 2.3 10⁴intheintegratedsamples)andpercentageofobserveddMdingcells(upto3l%),appearedin August, and formed a maximum in the thermodine. Cellnumbers were minimal when upwelling caused a breakdown of stratification.Fligh numbers of D.acuta (up to 1.8 10⁴ cells 1^–1 appearedagain when persistent south winds in late October caused a reversalof the circulation. Thus, the two cell maxima occurred duringtwo distinct hydrographic regimes, but in both cases at temperaturesof 15–17C. Numerous cells with one typical D.acuta valve,but the other valve reduced in size, were seen during the bloom,as well as Dinophysts dens Pavillard cells that might be a lifecycle stage of D.acuta. Other observations include double- walled,unwinged forms that are perhaps some kind of cyst, and a hypothetical‘fertilizing tube’ emerging from the larger cellof a D.acuta/D.dens couplet. It is suggested that the maximaduring stratification and during downwelling episodes couldcorrespond to periods with a predominance of in situ growthand physical accumulation, respectively, and that the exceptionalmeteorological conditions during 1989 provided the optimum scenariofor the unusual occurrence of D.acuta.     

Enzymatic Isolation of Protoplasts from Fern Protonemal Cells Stainable with a Fluorescent Brightener

Protoplasts were successfully isolated for the first time fromthe filamentous protonemal cells of ferns after the cells werecultured in contact with both air and medium. Sterilized sporesof Adiantum capillus-veneris and Pteris vittata were inoculatedon a piece of nylon mesh (40- {diaeresis}m mesh) placed on amat of polyester fibers which was soaked in liquid culture medium,and the spores were illuminated from above with continuous redlight. Protonemal cells, exposed to the air during this procedure,could be stained with Calcofluor White, a dye that binds tocell walls. Protoplasts were easily isolated from these protonemalcells by digestion of the cell wall with cellulase and pectinase.A total of 0.8–1.9 x 10⁴ and 0.6–2.0 x 10⁴ protoplastswere obtained from protonemata that originated from 10 mg ofdry spores of Adiantum and of Pteris respectively. Viability,as judged by staining with fluorescein diacetate was more than90% for both species. Staining with 4'6-diamidino-2-phenylindole(DAPI) revealed that about half of the protoplasts of both speciescontained a nucleus. (Received May 22, 1989; Accepted September 5, 1989)     

SEXUAL STRUCTURE OF A TRIDACNA SQUAMOSA POPULATION: RELATIVE ADVANTAGES OF SEQUENTIAL AND SIMULTANEOUS HERMAPHRODITISM

The sexual structure of a Tridacna squamosa population fromthe South China Sea was analysed. From a study of smears andslides of gonads of 54 clams, 24 of the smallest and youngestindividuals of 0.1–1.8 kg gross body weight were foundto be phenotypic males, 28 of the larger individuals of 0.9–9.2kg gross weight were simultaneous functional hermaphrodites.The relative proportion of the female part increased with ageand growth in the gonad of hermaphrodites, and in the two largestindividuals, of 10.5 and 13 kg gross weight, pure female aciniwere observed. The population had a pronounced size/age structure.The soft-body weight of the largest and oldest individuals was100–150 times that of the smallest and youngest ones.The population was also of low density, with 1 individual per40–50 m². These are the suggested reasons for the fusionof sequential and simultaneous hermaphroditism in the sexualdevelopment of T. squamosa. (Received 4 August 1989; accepted 1 June 1991)     

Long-Term Phosphate Starvation and Respiratory Metabolism in Suspension-Cultured Catharanthus roseus Cells

In order to clarify the metabolic adaptation of respiratorypathways in plants to limited levels of P_i, the effects of long-termstarvation of P_i on the activities of various enzymes relatedto respiratory metabolism were examined in suspension-culturedCatharanthus roseus cells. When the activities were expressedas units per g fresh weight, only those of phosphoenolpyruvate-hydrolyzing(PEP-hydrolyzing) enzyme (which may possibly be equivalent tothe acid phosphatase activity derived from vacuoles) and PEPcarboxylase were higher in the Pⁱ-starved cells than in controlcells. Activities of other enzymes in the Pⁱ-starved cells werelower than or similar to those of the control cells. Time-coursestudies indicated that PEP-hydrolyzing activity was inducibleby starvation of Pⁱ. However, in contrast to the results reportedby Duff et al. [(1989a) Plant Physiol. 90: 1275.], fluctuationsin the activity of PP¹:fructose-6-phosphate 1-phosphotransferaseduring starvation of Pⁱ were similar to those in levels of phosphofructokinaseand 6-phosphogluconate dehydrogenase. These data suggest thatthe concept of the phosphate starvation-inducible ‘bypasses’,which are engineered via the coarse control (i.e., induction)of specified enzymes and were proposed initially by Duff etal. in Brassica nigra cells, is not directly applicable to Catharanthusroseus cells in suspension. Tracer experiments using [U-¹⁴C]glutamineindicated that a significant proportion of respiratory substratescould be supplied from the enlarged pool of amino acids duringstarvation of Pⁱ. These assumptions are supported by the observedfluctuations in levels of free amino acids and of protein inP¹-fed and P¹-deficient Catharanthus roseus cells. ¹Part 41 in the series ‘Metabolic Regulation in PlantCell Cultrue’ ²Present Address: Morinaga Mild Industry, 5-1-83, Higashihara,Zamma-shi, Kanagawa, 228 Japan     

A study of feeding in predacious ciliates using prey ciliates labeled with fluorescent microspheres

Feeding in predacious estuarine ciliates was investigated ina series of laboratory experiments using a new method of preylabeling which facilitates microscopic indentification of ingestedprey items. Ingestion rates of Mesodinium pulex, Euplotes vannusand E.woodruffi were estimated using the appearance, insidethe predator, of bacteriovorous ciliates (Metanophrys sp., Cyclidiumsp.and Pleuronema sp ) labeled with fluorescent microspheres. Preyremain motile and have presumably unaltered surface characteristics.Ingestion rates of log-growth phase predators increased withprey density. Mesodinium pulex ingested 0 15–0.32 cellsh^–1 over a prey concentration of 60–2300 ml^–1.Maximum ingestion rates of E. woodruffi and E. vannus were 4.5and 3.4 cells h^–1 respectively, estimated at prey abundancesof 75 and 172 cells ml^–1 respectively. Comparisons offeeding rates on prey of different sizes, and the effects ofstarvation, indicated that ingestion is likely limited by differentfactors in ‘raptorial’ (M pulex) and ‘filterfeeding’ (Euplotes spp.) predators.     

CHLOROPHYLL AMOUNT AS AN INDICATOR OF MATTER PRODUCTIVITY IN BIO-COMMUNITIES

The data of chlorophyll amounts in diverse bio-communities arecompiled and discussed with reference to matter production. The chlorophyll amount in euphotic zone of lakes and oceanswas less than 1 g/m², mostly less than 0.1 g/m². In phytoplanktonblooms it was ca. 0.1–1 g/m². Large values of 5–20g/m² were obtained in the outdoor mass cultures of Chlorella,in which the high population density and chlorophyll contentof the alga were observed. In terrestrial higher plant communitiesthe chlorophyll amount (ca. 1–10 g/m²) was usually higherthan in aquatic phytoplankton communities. The largest (13.3g/m²) was obtained with an evergreen gallery forest in Thailand.The chlorophyll amount of desert bio-community could be expectedto be as high as that in water blooms. The maximum chlorophyll amount in bio-communities seems to attainup to 20 g/m² when the conditions are favorable. ¹ Dedicated to Prof. H. TAMIYA on the occasion of his 60th birthday. (Received December 25, 1962; )