Local anæsthesia: Its scientific basis and practical use. Prof. R. Heinrich Braun. Translated and edited by Percy Shields, M. D., Cincinnati, from the third German edition. Quarto. Pp. 399, with 215 illustrations. London: Henry Kimpton. 21s. net

1915 ◽  
Vol 3 (9) ◽  
pp. 155-156
2022 ◽  
Vol 354 (11-12) ◽  
pp. 97-99
Author(s):  
M. A. Starostina ◽  
N. G. Lapenko

Relevance. Biological features (morphometric indicators, viability and germinating power) of Poterium polygamum seeds found in natural communites of the Stavropol Territory have been studied. The conservation of wild-growing plant species in the natural population and the rational use of their potential are relevant.Methods. Years of study — 2013–2021. The subject of the study is Poterium polygamum seeds. Seeds were collected in 2013. Studies were carried out according to the methods of studying seed material. Freshly harvested seeds and seeds of different shelf life were germinated in petri dishes at a temperature of 18–20 °C.Results. The collected seeds of Poterium polygamum are quite large. The length of the seeds is 4–5 mm, the width is about 2.5 mm. The mass of 1000 pieces of seeds on average was 10.59 grams. Complete absence of viability of freshly harvested Poterium polygamum seeds was revealed. After three months, seed viability was 97%. This is a shallow physiological rest associated with the post-harvest maturation period. During the storage of seeds, their high germination was established — from 70 to 100%. The duration of seed storage is 8 years. The largest number of germinated seeds and their germinating power were noted in the third year of their storage (100%). Seeds germinated on the third or fourth day. The differences between the viability of seeds and their germinating power are not great. In the eighth year of storage of Poterium polygamum seeds, viability and germinating power were slightly reduced. The storage period of seeds, in which they retain the ability to germinate and the germinating power, is long. It has been found that the wild species Poterium polygamum belongs to plants with a high (70 to 100%) viability. This species is regularly resumed in the natural population. The revealed biological features of Poterium polygamum seeds can become the scientific basis during the reconstruction of degraded natural grass stand and in selection work.


1982 ◽  
Vol 9 (1) ◽  
pp. 65-70 ◽  
Author(s):  
E. Barton Worthington

The historical perspective is becoming ever more important in scientific research and development—especially in regions of rapid political and social change, such as former colonial empires, where the past is readily forgotten. Therefore this essay attempts to reconstruct the evolution of Ecology as the scientific basis for environmental conservation and human progress, as seen through the eyes of a biologist who has exercised that science during a number of tasks in various parts of the world over most of the twentieth century.From its beginnings in evolutionary thinking during the nineteenth century, ecology emerged from natural history at the beginning of the twentieth. At first the running was made by botanists; but this was soon followed by zoologists, who dealt with more mobile communities. The first quarter-century was mainly exploratory; the second was mainly descriptive (although biological exploration was still dominant in the tropics). The third quarter saw ecology developing into an experimental science, and, as the environmental revolution got into its stride, ecology became organized both nationally and internationally.Although the term is now often misused and sometimes misunderstood by laymen, the last quarter-century is seeing the wide application of ecology in environmental and human affairs, and this gives some assurance that the twenty-first century will not become one of chaos. The Author expresses the hope that experienced practising ecologists will in future give higher priority to applying what they already know than to learning more and more about less and less.


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