5 pages, 4 figures | El fin de la Sagrada Escritura no es la instrucción científica; pero, sin embargo, contiene acabadas descripciones científicas. Y la de las primeras plagas de Egipto es una de ellas. [...] Plancton, antoplancton, Euglena proxima, Euglena polimorpha, Euglena pisciformis, Chrysococcus rufescens, Chlamydomonas pertusa, Gonium pectorale, Dictyosphaerium ehreberglanum, Richteriella botryoides, Scenedesmus quadricaula, Selenastrum sp., Tetraedron minimum var. scrobuculatum, Pseudononas, Chromatium, Gonium sociale, Microcystis, Chromulina, Chromophyton, Chryptomonas, Peridinium, Sphaerella lacustris, Haematococcus, Euglena sanguinea, Artemia, Trichodesmium erythraeum, Brachiomonas, Platymonas, purga de mar, Gonyaulax [...] | Peer reviewed

A retenção de água pelo solo se deve exclusivamente a fôrças capilares. Tôda divisão da água do solo é convencional. Quando se utiliza a equação y = xT / x + qT no estudo de processos que tendem para um valor final, a velocidade do fenômeno é dada por 1/q. Ê possível calcular para os solos do Estado de São Paulo a Umidade de murchamento por meio da Umidade equivalente. U. mu. = 0,68 U.Eq. Não se pode, em geral, aplicar com sucesso as fórmulas de Vageler e Alten para o cálculo do Hy em função dos trocáveis. O Hy do solo não se altera fazendo variar o tempo de secagem na estufa (105° - 110° C) antes da determinação. Os valores máximos dos dados referentes à água do solo foram encontrados na terra roxa legítima e os mínimos no Arenito Botucatu. | The retention of moisture by soil is conditioned exclusively by capillary forces. Any division of soil water is merely conventional. Using the formula y = xT / x + qT to compute the final value of a process, it is important to note that the velocity of the phenomenon is given by 1/q • For the major soil types of the State of São Paulo it is possible to calculate the wilting point by means of the moisture equivalent using the formula Wp. = 0,68 M.Eq. In general, the formulae of Vageler and Alten for computing hygroscopicity by means of exchangeable-ions are inadequate. Different periods of exposure of soils to temperatures of 105° - 110°C. before determinations are made do not exert a pronounced influence on hygroscopicity. The highest values for water-holding capacity were obtained in the terra roxa legítima and the lowest in the Botucatu sandstone.

Using the method of Briggs and Shantz, several types of soils of the State of São Paulo were studied respecting their wilting points. The results obtained are given in the Table I, and show us that we cannot use as wilting point twice the value of the hygroscopicity as given by Camargo and Vageler for the soils of the State of São Paulo.

9 pages, 3 figures | [EN] New localities of freshwater Ostracoda in northeastern Spain are recorded and complemented with ecological remarks. Potamocypris pyrenaica, from the Pyrenees, is described as a new species, closely related to P. wolfi Brehm and speeially to P. illinoisensis Hoff. P. pyrenaica may be differentiated readily from the last species in having the ductus eiaculatorius with more numerous supporting rays and the penis somewhat different. P. pyrenaica is one of the rare european Potamocypris known to occur in both sexes. A unique fall of duplication of the flagellum of the furca has been recorded in a female of the new species. [...] Cypria ophthalmica (Jurine), Ilyocypris bradyi G. O. Sars., Heterocypris incongruens (Ramdohr), Potamocypris yillosa, Diacyclops bicuspidatus var. odessana, Herpetocypris reptans (Baird), Cypridopsis vidua (O. F. Miiller), Potamocypris wolfi Brehm 1920, P. julva, Potamocypris villosa (Jurine) [...] | [ES] La presente nota continúa y complementa la que fué publicada en el volumen anterior de esta revista (MARGALEF (1946a)). A la bibliografía sobre ostrácidos españoles de agua dułce allí indicada debe adicionarse un trabajo de PARIS (1920) en el que se describe la especie Candona breuili, procedente de Candarno (Asturias). En las siguientes líneas, cuando no se indica nada en contraria, debe entenderse que las recolecciones indicadas contenían ejemplares adultos (♀♀ ovíferas). Se dan las altitudes sobre el nivei del mar de las localidades situadas a más de 500 metros. [...] | Peer reviewed

34 pages, 10 figures, 10 tables | [EN] The larvae of Aedes áegypli and those of other culicidae are most frequently found in transient stares of a succession developping in polluted waters. A most precise description of these facts was obtained by experimenting in a series of containers, each of 40 l. capacity. All these containers were man- tained under the same conditions of volume, surface, agitation, light, temperature and opportunities for colonisation. The succession was initiated bv the .addition of 0,5 g. pepton per liter (2, 4, 6). Control aquaria (1, 3, 5) remained unpolluted. The general ecology and the development of life is to be seen in tab. I-VI and fig. 1-7. Three stages may be distinguished along the succession : 1) Plénty of organic matter, oxygen exhausted, a great quantity of bacteria, bacteriophagous and saprozoic ciliata, some green protist which are able to take in aminoacids, the ostracod lleierocypris incongruens remains active, larvae of psychodidae. 2) Oxygen increases up to oversaturation owing to a great development of green nannoplankton, the larvae of ceratopogonidae displace those of psychodidae. 3) Enough oxigen and greenalgae, but less than in 2), the ostracod Cypridopsis Newtoni displaces Heterocypris, appearance of the larvae of Aedes while those of other díptera disappear. The whole image of the succession is very typical, but the speed of the succession is regulated by some factors : a) Chemical : the succesion is slower in more concentrated waters, b) biotic : Pseudomonas act as a retárdative upon the succession. [...] Pecton, Scenedesmus, Hydrococcus, Scenedesmus, Euglena, Rhodomonas af. Iacustris, Gymnodinium af. veris, Glenodinium sp., Navicula (Schizonema) sp., Lutherella (?) sp., Dispora crucigenioides (?), Chilodonella af. capucina, Dermocarpa parva, Hydrococcus opertus nov. sp., Chlorella, Bacteriaceae, Cyanophyceae, Chroococcus minor (Kütz.) Nág., Ch. minutus (Kütz.) Nág., H. rivularis Kütz., H. Cesatii Rabh, Dermocarpa parva (Conrad) Geitler, Cladophora, Oscillatoria chalybea Mertens f.ª, O. formosa Bory, O. splendida Grev., Flagellatae, Dinoflagellatae, fíodo minimus Klebs, Tetramitus descissus Perty, Rhodomonas af. lacustris Pascher & Ruttner, Cryptomonas pusilla Bachmann, Cryp tomonas erosa Ehrenb., Cyathomonas truncata (Fres.) Froment. f.ª, Euglena pisciformis Klebs., Notosolenus apocamptus Stokes, Peranema trichophorum (Ehrenb.) Stein, Gymnodinium af. veris Lindem., G. edax Schill., G. pallidum Skuja, Peridinium pusillum (Penard) Lemm., Bacillariophyta, Cyclotella Meneghimana Kíitz, Fragilaria construens (Ehrenb.) Grun., Synedra acus Kütz, S. acus var. radians (Kíitz.) Hustedt., Achnanthes minutissim Kütz, S. ulna (Nitzsch) Ehrenb., Eunotia pectinalis Rabh. var. minor (Kíitz.) Rabh., Cocconeis placentula Ehrenb., C. pediculus, Navícula radiosa Kütz, Navícula (Schizonema) sp., N. confervacea (Kütz.) Grun., Pinnularia viridis (Nitzsch) Ehrenb., Gomphonema constrictum Ehrenb., Gomphonema intricatum Kütz, Cymbella microcephala Grun, Amphora ovalis Kütz. var. pediculus (Kütz.) Grun, Nitzschia communis Rabh., N. sigmoidea (Ehrenb.) W. Sm., Heterocontae, Lutherella (?), L. adhaerens Pascher, E. nitellae Geitler, Chlorophyceae, Gonium sociale (Duj.) Warming., Sphaerella lacustris (Girod) Wittr. ( = Haemcitococcus pluvialis Flot), Dispora crucigenioides (?) Printz, Pediastrum Boryanum (Turp.) Ask. var. Boryanum. (Turp.) Mor. Wod., Chlorella conglomerata (Artari) Oltm., Chlorella coelastroides Cliodat, Chlorella «vulgaris» Beijeriuck, Lagerheimia (Chodatella) quadriseta (Eeinm.), Dictyosphaerium Ehrenbergianum Nág., Scenedesmus abundans (Kirch.) Chodat, S. acuminatus (Lagerh.) Chodat, S. armatus (Chodat) Smith, var. Chodatii Smith, var. subalternans Smith, Scenedesmus longispina Chodat, f.ª bicaudatus, S. obliquus (Turp.) Küitz, S. quadricauda (Turp.) Bréb., Ankistrodesmus convolutus Corda var. minutum (Nág.) Rabh., A. falcatus (Corda) Ralfs., var. spirilliformis G. S. West., var. acicularis (A. Br.) G. S. West., Rhizoclonium hieroglyphicum (C. A. Ag.) Kútz, Cladophora fracta Kiitz. ampl. Brand., C. crispata, Conjugatae, Cosmarium laeve Rabh., Cosmarium vexatum West., Rhizopoda, Vahlkampfia sp., Amoeha limicola Rhumbler, Oedogonium, Nitzschia linearis, Chlamydomonas, A. radiosa Duj., Ciliata, Coleps hirtus Nitzsch., Lionotus fasciola Ehrenb., Chilodonella af. capucina Penard., Saprophilus pyriformis (Ehrenb.) (= Glaucoma pyriformis), Cyclidium glaucoma O. F. Müll., Stentor Roeselii Ehrenb., Euplotes affinís Duj., Aspidisca costata Duj., Vorticella similis Stokes, V. microstoma Ehrenb., Saprophilus, Rotataria, Cephalodella gracilis (Ehrenb.), Lepadella af. patella (O. F. Müll.), Anuraeopsis fissa (Gosse.), Crustacea, Cyclops (Tropocyclops) prasinus P'ischer, Heterocypris incongruens (Ramdohr),Cypridopsis Newtoni Brady & Robert, Cyclops prasinus, Díptera, Aedes aegypti L. ( = A. fasciatus Mg. =A. argenteus Poir.), Culex, Theobaldia [...] | [ES] En una nota anterior (MARGALEF, 1944) fundada en observaciones circunstanciales de carácter más bien "extensivo", llegaba a la conclusión de que la residencia ecológica propia de las larvas de un grupo de mosquitos, era la "constituida por medios estancados, caracterizados por una alteración rápida en sus características; por una brusca ruptura del equilibrio en la economía del agua que se presenta cuando existe exceso de materia orgánica por oxidar» y estimaba «el estudio práctico de las características de tal ambiente susceptible de revelar la naturaleza de algunos factores indispensables al desarrollo de las larvas». Esto parecía señalar el camino de ataque a la resolución de un importante problema de ecología, que debía emprenderse estudiando «intensivamente» algunos biotopos más o menos típicos, con sus comunidades, en los cuales pudieran reproducirse a voluntad las condiciones que el estudio «extensivo» preliminar había sugerido que eran favorables al desarrollo de los culícidos. [...] | Peer reviewed