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| Registros recuperados: 285 | |
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| Carvalho,A.; Krug,C. A.. |
| This paper describes the methods used and presents an analysis of the results obtained from three years of study, to determine the separate and inter-related effects of various agents such as gravity, wind and insects, in the pollination of flowers of Coffea arabica L. Observations were made and data obtained from several thousands of normal and castrated flowers that were maintained under natural and controlled conditions. It has been found that the importance of gravity, wind, and insects in pollination of the flowers may vary appreciably in relation to local environmental influences. The data obtained, however, indicate certain trends that are of definitive interest. Based on the total number of ovules, it was found that in 1228 normal flowers observed,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1949 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051949000100002 |
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| Horst, C.J. van der. |
| At the seventh International Zoological Congres at Boston, HUBRECHT (1907) delivered an address “On the foetal membranes of the Vertebrates”. In this lecture he expounded his revolutionary ideas about the origin of the foetal membranes and the phylogenetic history of the vertebrates in general. HUBRECHT was of the opinion that in the ancestors of the Mammalia there was only one embryonic membrane, and that has been retained as the the trophoblast. Its original function was to protect the larva, but when, in the early mammals, intra-uterine development was established, this membrane assumed the function of feeding the embryo as we see in our present day mammals. In order to function properly a connection was then established with the embryonic vascular... |
| Tipo: Article / Letter to the editor |
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| Ano: 1949 |
URL: http://www.repository.naturalis.nl/record/504498 |
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| Stevens,W. L.. |
| This paper describes the statistical analysis of a varietal trial with two unusual characteristics : (i) The plant (coffee) is one of those which show strong maxima and minima of production in alternate years. This phenomenon must be prevented from masking or biasing the other varietal comparisons in which we are interested. (ii) The design of the experiment is systematic. It was laid down in Campinas, Brazil, in 1933 at a time when the principles of randomisation were not so widely known as they are today. THE EXPERIMENT AND DATA. Six varieties are compared, denoted by A B C D E and F (see page 104). They are planted in thirty rows, each with 50 plants, according to the systematic design : A B C D E F A B C D E F A B C D E F A B C D E F A B C D E F Data... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1949 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051949000200002 |
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| NN. |
| Baas Becking, L.G.M.: Notes on jungle trees I (Chron. Nat. 104, 1948, 271-277). Calculation of the age of the stand in the mountain forest reserve Tjibodas on Mt Gedeh, W. Java, by means of new measurements on the trees numbered by S.H. Koorders in 1890. By means of the losses (0.77% annually) the average life span of a tree is estimated at ca 130 years. Backer, C.A. c.s.: Beknopte Flora van Java (nooduitgave) afl. VII. Fam. XCLVIII-CLXXII. Rijksherbarium, Leiden. Sept. 1948. This instalment of the mimeographed emergency edition (in Dutch) contains the treatments of Meliaceae, Sapindaceae, Aceraceae, Sabiaceae, Staphyleaceae, Anacardiaceae, Connaraceae, Juglandaceae, Cornaceae, Alangiaceae, Nyssaceae, Araliaceae, Umbelliferae, Clethraceae, Ericaceae,... |
| Tipo: Article / Letter to the editor |
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| Ano: 1949 |
URL: http://www.repository.naturalis.nl/record/532951 |
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| Registros recuperados: 285 | |
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