ALBERT

Description: The present paper is an extension of my revision of the Malaysian species of the genus Dillenia L. (Wormia Rottb. included) inserted in the revision of the Dilleniaceae in the Flora Malesiana ser. I, vol. 4, part 3, pp. 141\xe2\x80\x94174, published in December 1951. A critical revision of the whole genus has never been published before; the unfortunate result of this has been that the delimitation of Dillenia and Wormia, usually as distinct genera, has been based on different characters by various authors. The extension of the revision for the Flora Malesiana so as to include the extra-malaysian species enabled me to study a number of species, the knowledge of which certainly confirmed me in my idea that the characters on which Dillenia and Wormia had been separated before are certainly not the primary characters, to be used in the taxonomic treatment of the genus.\nAll specimens and literature mentioned in this work have been examined by me, unless indicated otherwise; excepted are the specimens of the U.S. National Herbarium., of which I have only examined those collections, of which no duplicates were available from other herbaria. Particulars, not to be taken from the herbarium specimens themselves, such as habit, height, diameter, colour, etc., have been taken from the collectors\xe2\x80\x99 notes and, as far as reliable, from the literature, and are inserted in the descriptions; if there are contradictory data, they are discussed under the Notes.

Description: Trees with leaves crowded at tip of thick branchlets; stipules subulate or narrowly deltoid, caducous; leaves, obovate or obovate-oblong, tertiary nerves ascending near the midrib, transverse near the margins of the leaf; flowers crowded at tips of branchlets, forming a pseudo-terminal, many-florous inflorescence; calyx with two whorls of two lobes each; corolla exsert, tube solid, pubescent without at apex, petals 8, imbricate; stamens 9\xe2\x80\x9440, inserted in one or two rows in the throat; style subulate, exsert, glabrous; ovary glabrous, 3\xe2\x80\x948-celled, cells 1-ovuled, ovules attached at the apex of the central axis; sometimes an indistinct annular disc present; fruit large, often edible, crowned by the persistent style; fruit usually 1-seeded; seed ovoid with large to very large scar and apical hilum; testa thick, crustaceous; albumen none or membranous, if present especially around the radicle; cotyledons fleshy; radicle inferior, not exsert \xe2\x80\x94 11 species distributed from the Moluccas to the Samoa and Tonga Islands.\nThe last revision of this genus was given by Lam in 1942. After a small but important publication of White (J. Arn. Arb. 31, 1, 1950, 104) and the investigation of some new collections it seemed appropriate to give a concise revision of this genus in preparation for the \xe2\x80\x9cFlora Malesiana\xe2\x80\x9d. Some new species are described and of some old ones more details are given. The publications of Lam are abbreviated as follows: 1925 = The Sapotaceae, etc. of the Dutch East Indies, Bull. Jard. Bot. Bzg, s\xc3\xa9r. 3, 7, 1925, 112. Lam 1927 = Further studies etc., Bull. Jard. Bot. Bzg, s\xc3\xa9r. 3, 8, 1927, 381. Lam 1932 = Sapotaceae, in Nova Guinea 14, 4, 1932, 554. Lam 1942 = A tentative list of wild Pacific Sap. etc., Blumea 5, I, 1942, 36.

Description: In January 1949 Professor H. J. Lam, director of the Rijksherbarium, Leyden, on his way to the 7th Pacific Science Congress in New Zealand, spending some time in Fiji, was shown by Mr B. E. V. Parham, Department of Agriculture, Suva, Viti Levu, Fiji Islands, a slender tree, cultivated in the Agricultural Experimental Garden Naduruloulou. The tree was unidentified and of unknown origin. Some flowering material was collected and at our request Mr Parham was good enough to send some ripe fruits in liquid for an investigation I was entrusted with.\nAdditional material was studied from the herbaria at Brisbane, Kew, Leiden, Melbourne and Paris. It is my pleasant duty to tender my best thanks to the directors of these institutes for the loan of this valuable material, among which the type.

Description: With reference to and in continuation of our elaborate announcement in Blumea VI, nr. 2, 1950, p. 544\xe2\x80\x94545, it is a pleasure to report now the publication of Vol. I, entitled: Malaysian plant collectors and collections, being a cyclopaedia of botanical exploration in Malaysia and a guide to the concerned literature up to the year 1950 by Mrs. M. J. van Steenis\xe2\x80\x94Kruseman (CLII + 639 pp., 3 maps and about 220 illustrations).\nThe General Part (roman page numbers) comprises introductory paragraphs (aim of work, interesting data and hints on labeling, lists of illustrations and literature of use to collectors and investigators, terminology of altitudinal zones, and the use of vernacular names) as well as chapters on the technique of botanical exploration and collecting, on the phytogeographical delimitation and subdivision of Malaysia, on the collections made in the area concerned (arranged both chronologically and geographically, with 1 map), statistics of collections and desiderata for further exploration with 2 maps), sources consulted for the data mentioned (literature and herbaria), and samples of handwritings of 70 collectors and botanists.

Description: As early as 1939 I started a study of Papuan Nothofagus, and since 1948 I was entrusted with the elaboration of all the material my colleagues could lay hands on. This work was repeatedly interrupted on account of official duties. Pending the full account of the work in the Journal of the Arnold Arboretum I regret that it seems necessary to safeguard my conclusions as soon as possible.

Description: In my paper on Parmeliaceae (in Blumea, vol. 6, 1947) some remarks have been made concerning the taxa below the rank of species (p. 3\xe2\x80\x944), one of them being the statement that I was to try to hold an intermediate course between those authors accepting multitudes of varieties and forms, and others abandoning them all. In the eyes of both I may have failed.\nIn the present paper I am going to alienate myself still farther from the former group of authors in reducing varieties to forms and doing away with many other forms. Although in a way this contradicts my inclination towards a meticulous classification in my former paper, it should be borne in mind that not all genera in lichenology can be treated alike. I still believe in varieties and forms \xe2\x80\x94 considering e.g. Parmelia physodes very good illustration \xe2\x80\x94 but on the other hand I am well aware now that in following Hillmann, whom I shall always gratefully remember for his kind help during the early days of my lichenological training, I have been decidedly all too punctilious.

Description: La stratification des roches cristallines (d\'\xc3\xa2ge ant\xc3\xa9st\xc3\xa9phanien) des massifs centraux des Alpes est en g\xc3\xa9n\xc3\xa9ral \xc3\xa0 peu pr\xc3\xa8s parall\xc3\xa8le \xc3\xa0 la schistosit\xc3\xa9. \xc3\x89galement les intrusions granitiques y sont plus ou moins concordantes.\nCependant les recherches sous la direction du Professeur E. Niggli de Leiden ont d\xc3\xa9montr\xc3\xa9 que le contact est du massif granitique des Sept-Laux (Massif de Belledonne s. 1.) est concordant seulement en grandes lignes avec la schistosit\xc3\xa9, tandis qu\'il est parfois nettement discordant en d\xc3\xa9tail (voir la publication dans un des num\xc3\xa9ros suivants de ce p\xc3\xa9riodique).

Description: Miopliocene marls from the island of Buton yield a large marine foraminiferal fauna and some calcareous algae. Three-hundred and thirthy-three species have been identified. Two genera, twenty-three species and four varieties are described as new.\nThe existence of mud-volcanoes in young neogene time is advocated.

Description: Identification of natural alkali felspars with X-ray powder photographs.\nX-ray powder analysis is becoming an important tool for the petrographer when identification problems can not be solved with the usual optical and chemical methods.\nIt is the aim of this paper to provide data to identify alkali felspars in groundmasses of extrusive rocks, perthites and other fine grained structures. Moreover the variation of the intensities and the position of spacings of the powder patterns of natural alkali felspars is compared with the variation in optical properties and chemical composition.\nTo this purpose alkali felspars of different localities, chemical composition, crystallization temperature and rate of cooling are investigated with optical methods, X-ray powder analysis and as far as possible, chemical analysis.\nThe optical examination of the alkali felspars was made with the four axes universal stage. The position of the poles of crystallographic elements and twinning axes was determined with respect to the axes of the indicatrix N\\u03b1, N\\u03b2, N\\u03b3. The co-ordinates are recorded according to Nikitin (1936). The quadrant in which each pole is situated is indicated by the sign + or \xe2\x80\x94.\nIn plate III the measurements on the potash-soda felspars are plotted in a projection normal to N\\u03b21. The interpretation normal orthoclase-Naorthoclase was made with the aid of the co-ordinates given by Nikitin (partly reproduced in table I) who did not give a chemical definition of these terms. The available chemical data in this investigation proved that thus defined normal orthoclase contained 〈 25 % Ab and Na-orthoclase 〉 25 % Ab in solid solution. Determination of refractive indices was used to distinguish anorthoclase from both \xe2\x80\x9clow temperature\xe2\x80\x9d albite and potashfelspar.\nThe alkali felspars investigated were grouped according to their natural paragenesis. Crystallization temperature, rate of cooling and stability within these groups are discussed. 1. Alkali felspar phenocrists from extrusive rocks.\nLarge sanidine phenoerists (d. 5,5 m.m.) from Lagno de Pollena, Vesuvius, show a zoned structure // (010), (fig. 3).\nIn sanidine of Siebengebirge wedged in between large homogeneous crystals (d. 8\xe2\x80\x9410 m.m.) appear small zoned sanidine crystals (d. 1\xe2\x80\x943 m.m.) which show polysynthetic twinning lamellae in many directions (fig. 2). Probably this is a product of later crystallization under stress.\nAnorthoclase of Puy de D\xc3\xb4me (fig. 7), Pantelleria and Mnt. Anakie, Australia (fig. 4) show an extremely fine albite twinning which seems to be typical for anorthoclase. Refractive indices (n\\u03b3=1,529) and X-ray powder pattern (fig. 18) are characteristic and different from those of \xe2\x80\x9clow temperature\xe2\x80\x9d albite.\nIn trachites of Colli Euganei, Italy, phenocrists were observed (fig. 5) with a core of \xe2\x80\x9chigh temperature\xe2\x80\x9d oligiclase (26 % An, 2V=\xe2\x80\x9484\xc2\xb0) passing in a rim of anorthoclase (2V=\xe2\x80\x9460\xc2\xb0). This proves the existence of a continuous series of solid solutions between h.t. oligoclase and anorthoclase. 2. Alkali felspars from plutonic rocks and dykes.\nExamples of cryptoperthites, orthoclase- and microcline microperthites and untwinned microcline are described. 3. Alkali felspars from pegmatites.\nDifferent structures of microcline perthites are described. In fig. 15 is shown how vein albite // (001), with an irregular surface regulates the position of adjacent microcline twinning lamellae. In this case the microcline twinning lamellae seem to be younger than the vein albite. On the other hand simultaneous crystallization as suggested by Spencer (1938, p. 107) seems not impossible. The most frequent occuring type of vein albite in microcline is reproduced in fig. 23, cutting the microcline lamellae under an angle of 60\xc2\xb0 with the (010) cleavage in (001). The vein albite is consequently younger than the microcline. Therefore Andersens (1928) suggestion that this vein albite is produced by infiltration of albite solutions in oriented shrinkage cracks may explain the constant orientation of the vein albite. Spencer\xe2\x80\x99s hypothesis of the cotectic origin of vein albite can only hold for isolated examples as mentioned in the description of fig. 15. The majority of vein albite in microcline is of secondary origin.\nExamples of patch perthite produced by replacement are shown in fig. 14 and fig. 24. As examples of \xe2\x80\x9chigh temperature\xe2\x80\x9d pegmatites a cryptoperthite from Larvik, Norway, and orthoclase from Itrongay, Madagascar, are described.\nA number of crystals of the well known monoclinic \xe2\x80\x9corthoclase\xe2\x80\x9d of Baveno produced X-ray powder patterns characteristics for microcline with additional albite reflections. Optical examination showed that these crystals are strongly altered to kalinite and invaded by secondary albite (see Baveno twin of fig. 8). Other crystals showed recrystallization of fine grained microcline and albite (fig. 9). With high magnification an initial microcline twinning is observed (fig. 10).\nIt seems probable that most crystal of Baveno \xe2\x80\x9corthoclase\xe2\x80\x9d on display in mineralogical musea, on optical examination will be found to show a pseudomorphosis of orthoclase by microcline. 4. The adularia-albite paragenesis.\nIn most of the examined adularia crystals from St. Gotthard, Bristenstock and Maderanerthal locally triclinic lamellae were observed which show extinction angles of 2\xc2\xb0\xe2\x80\x946\xc2\xb0 with the (010) cleavage in (001). These triclinic zones are nearly always situated round inclusions (fig. 21) and may be found in the core as well along the faces of the crystals. They are to be compared with the triclinic zones found in sanidine (fig. 2). Axial angles and extinction angles are different from microcline.\nChemical analysis in weight percents of some of the alkali felspars investigated are listed in table 2 and fig. 16. The Or-Ab-An components are expressed in molecular percents.\nSiO2 values are generally too low and Al2O3 and Fe2O3 values to high. For the samples no. 4, 48, 49, 33 and 23 this may be explained by the occurrence of alteration products.\nX-ray powder photographs were obtained with an iron target, Mn filter and a 9 c.m. diameter Unicam powder camera. The diameter of the diafragma slit was 0,3 m.m.. Tube current and voltage were 18 m.A. and 40 k.V. respectively. The accuracy of the measurement of spacings was 0,02 m.m. corresponding with 1,9\xe2\x80\x99 \\u03c6. Measurements were corrected by the admixture of 10 % Nall. Intensities were estimated visually.\nExamining the powder patterns of the alkali felspars, five groups could be distinguished, classified independently of chemical composition and optical properties.\nGroup A (plate I A and II A and B).\nA similar pattern was observed for sanidine, orthoclase of plutonic rocks, dykes and pegmatites and hydrothermal adularia. Samples investigated are listed in table 8. In table 3 intensities, \\u03c6Fe- and d-values are recorded for St. Gotthard adularia and Drachenfels sanidine. Characteristic are the two strongest reflections (202) and (002) (040).\nGroup B (plate I B).\nAll microclines and untwinned microclines give a similar pattern which diff\xc3\xa9ra from the group A pattern by showing a single strong (002) (040) reflection followed by three groups of each three reflections with the same intensity (p, q and r in fig. 17). Intensities, \\u03c6Fe- and d-values are recorded in table 4. Samples investigated are listed in table 9.\nGroup C (plate I C).\nThe powder pattern data of \xe2\x80\x9clow temperature\xe2\x80\x9d albite are recorded in table 5. Samples investigated are listed in table 10. Additional albite reflections of orthoclase- and microcline perthites are indicated respectively with AC and BC in table 8 and 9.\nGroup D (plate II D).\nIn table 6 are recorded the intensities, \\u03c6Fe and d-values of a typical anorthoclase. The investigated samples are listed in table 11.\nGroup E (plate II C).\nIn table 7 the powder pattern properties are recorded of a ciwptoperthite with a high An-content.\nThe facts recorded in table 8\xe2\x80\x9412 show complete agreement between the classification of alkali felspars with powder patterns and the classification on optical properties. It is not possible tot distinguish between sanidine and orthoclase with the aid of powder photographs. So the optical properties seem to be more sensitive to small changes in structure.\nThe powder patterns of all felspars have the strong reflection (002) (040) in common. The powder patterns of the alkali felspars with the exeption of \xe2\x80\x9clow temperature\xe2\x80\x9d albite differ from those of the plagioclases by the possession of an isolated strong reflection (043) (062), (d=1, 79\xe2\x80\x941, 78, s in fig. 17 and fig. 18).\nCharacteristic for sanidine, orthoclase and adularia (group A) with a composition up to 45 % Ab is the strong reflection pair (202) and (002) (040).\nThe microclines (group B) are characterized by a single strong (002) (040) reflection followed by three groups of each three reflections of the same moderate intensity (p, q and r in fig. 17).\nThe anorthoclase powder pattern which differs distinctly from the \xe2\x80\x9clow temperature\xe2\x80\x9d albite pattern is distinguished from the other alkali felspars by the presence of an isolated reflection of moderate intensity with d=3,15 (t in fig. 18).\nThe distance between the two strongest reflections (202) and (002) (040) of the powder patterns of sanidine, orthoclase from plutonic rocks, dykes, pegmatites and adularia proved to vary nearly linear with the Ab-content contained in solid solution. The distances were measured with the microscope with low magnification (X 19). In fig. 19 the variation of the distance between (202) and (002) (040) expressed in minutes (\\u03c6) is plotted against the Ab-content in molecular percents, calculated out of the chemical analyses available of homogeneous crystals of group A. The strong reflection of anorthoclase (106) seems to be doubled under the microscope. The corresponding distance does not fit in the diagram of fig. 19. A similar variation diagram for group A is plotted in fig. 20 in which the distances between the reflectons a and b (indicated in table 3) are used. The more time consuming absolute measurements of the position of certain spacings may also be used for the determination of the composition (see table 3\xe2\x80\x947 and fig. 17 and 18).\nThe Ab-component of orthoclase- and microcline perthites was easily observed in the diffraction patterns. Comparison with artificial mixtures of \xe2\x80\x9clow temperature\xe2\x80\x9d albite with orthoclase and microcline are shown in plate I, D, E, F, G. Excepting a cryptoperthite of Larvik, Norway, with an exceptional high An-content (group E) the albite component of the cryptoperthites (f.i. moonstone from Ceylon) could be easily detected. As in most cases only the strongest reflections of the albite component were present, is was not possible to make ure that \xe2\x80\x9chigh temperature\xe2\x80\x9d albite was present 1).\nAs contrasted with the cryptoperthites the investigated anorthoclases of Puy de D\xc3\xb4me, Pantelleria, Colli Euganei and Mnt. Anakie, Australia, proved to be optical and roentgenographical homogeneous. Although no natural or artificial \xe2\x80\x9chigh temperature\xe2\x80\x9d albite was available for investigation it seems probable that the powder pattern of anorthoclase (plate II D, table 6, fig. 18) must be similar to that of \xe2\x80\x9chigh temperature\xe2\x80\x9d albite.\nFelspars of rhomb porphyries, Oslo district, showed a powder pattern characteristic for oligoclase in agreement with the optical investigation of Oftedahl (1948).\nInvestigation of X-ray powder photographs of the plagioclases gave similar results as obtained by Claisse (1950). Powder patterns of anorthite from efflata of Monte Somma, Vesuvius (92 % An), anorthite of Pesmeda, Tyrol (94 % An) and anorthite of Kamitsuki, Miyake-Jima, Japan (98 % An), although very similar, showed differences in spacings and intensities which can not be explained by changes in composition. Differences in crystallization temperature and rate of cooling may be responsible for these structural differences.\nX-ray powder photographs of groundmasses of trachites, rhyolites, andesites, bostonites, pantellerites and helleflints showed the presence of alkali felspars, plagioclases and quartz (cristobalite, tridymite), see table 14. Comparison powder photographs of mixtures of quartz and felspar of known concentration permitted the estimation of the quartz content of the groundmasses.\nIn plate II E a powder photograph of charnockite is reproduced. With optical methods is was impossible to determine whether the mesoperthite present consisted of orthoclase- or microcline perthite.\nComparison with diffraction patterns of quartz (II F), a mixture of 80 % l.t. albite and 20 % quartz (II G) and a mixture of 80 % microcline and 20 % quartz proved the presence of quartz and microcline perthite in the charnockite.\nIn the last part of the paper the relation orthoclase-microcline is discussed and the existing opinions reviewed.\nThe hypothesis Mallard-Michel-L\xc3\xa9vy states that orthoclase consists out of submicroscopical twinned microcline units. The starting-point of this hypothesis is the supposed general occurence of intimately intergrown orthoclase and microcline. Now observations made by M\xc3\xa4kinen (1917), Baier (1930), Gysin (1928, 1938) and the present author tend to the conclusion that untwinned and partly twinned microcline are common; intergrowths of orthoclase and microcline however are limited to contactmetamorphic phenomena as described by Wimmenauer (1950). Triclinic lamellae in sanidine and adularia are not identical with microcline.\nThe influence of stress, advocated by Brauns (1891) as the cause of microcline formation is negligible, as is demonstrated by the common occurrence of free grown microcline crystals. The general occurrence of microcline in slightly metamorphosed rocks is due to the fact that these rocks attained equilibrium in the temperature region of 750\xc2\xb0\xe2\x80\x94500\xc2\xb0 C. (Spencer 1937, p. 481).\nOur optical investigation shows that there is a certain variation of the optical properties of microcline. A continuous change towards the optics of orthoclase was not observed. Considering these facts, together with the arguments put forward by Spencer (1938, p. 88), the submicroscopical twinning hypothesis seems improbable.\nAccording tot the hypothesis of Barth (1934), modified by Buerger (1948) microcline is formed by ordering of the Si and Al atoms with declining temperatures.\nThe difference in spacings and intensities found in the powder pattern of microcline indicates that the microcline structure shows a small distortion compared with the orthoclase structure.\nFinally the optical anomalies of adularia are discussed. The difference between the symmetrie relations of microcline and triclinic adularia is demonstrated in fig. 21 and 22.\nThe crystal structure of adularia seems to be similar to the orthoclase structure. Locally triclinic may originate round inclusions and disturbed areas during the crystallization. The structure of these triclinic lamellae is essentially different from the microcline structure originated by the complete ordering of the Si and Al atoms.\nContrary to the opinion of K\xc3\xb6hler (1948) it is evident that alkali felspars with an orthoelase structure crystallize at relatively low temperatures (450\xc2\xb0\xe2\x80\x94200\xc2\xb0 C.) which is also proved hy the occurence of authigenic felspar. Considering the polymorphism of the alkali felspars, exceptional conditions during the crystallozation must explain the formation of these \xe2\x80\x9clow temperature\xe2\x80\x9d forms.

Description: The deltas of the rivers Rhine, Meuse (Dutch: Maas), and Scheldt (Dutch: Schelde; French: Escaut) are connected so intimately that it is impossible to trace exact boundaries between them. Together they form a strip of Holocene deposits (clay, sand and peat), about 50 km wide, lying between the North Sea to the west and northwest and the Pleistocene region of the Netherlands to the east and southeast. The delta of the river Scheldt is the southern part of the joint deltas of the three rivers; it is nearly identical with the present province Zealand of the Netherlands.\nSecular fluctuations of the average level of the sea in relation to the land, both positive and negative, together with sedimentation and erosion, from the earliest times onward to the present day, continuously modified the local boundaries between land and water. The changing influx of salt water and the rate of drainage of the land always deeply influenced the vegetation and the whole character of the region. Moreover, since the Roman occupation in the beginning of our era, man had an ever increasing influence on the course of the river branches and on the water level in the rivers and ditches.