3 resultados para Projet BOT ou CET
em Aquatic Commons
Resumo:
The rhythm of division of 9 species belonging to different groups of algae were analysed in situ and in the laboratory. The research which developed in different environmental conditions attempted to establish the capacity for multiplication and assimilation of chlorophyll on the part of the algae under study with a view to placing them in a culture. The results obtained showed that the green multicellular algae (eg. Ulothrix) and the blue algae (eg. Lyngbya, Oscillatoria) are able to produce an appreciable quantity of dry matter, just as the unicellular algae. At the same time it arises that amongst the numerous factors of the environment, temperature plays one of the most important roles in the process of multiplication.
Resumo:
The most important aim of this study lay in filling in the great gap in our knowledge of the processes of germination in the Ceratium cyst and the early developmental stages in the standing stock of Ceratium hirundinella. contained rich cysts, we now succeeded extraordinarily well in pursuing the consistent development of Ceratium from the cyst to the completed cell. A series of experiments were carried out on the cysts and the juvenile stages of Ceratium, which showed very interesting results. The author presents in a general descriptive part the normal processes of germination in Ceratium cysts and the development of the juvenile stages in order to show in an experimental part the changes in form of C. hirundinella under the influence of temperature, light and varying salinities.
Resumo:
This information is based on the limnological observations of the very interesting and remarkable discharge of the Lunzer Obersee, (1117m). On journeying towards the Mittersee, the Lunzer Obersee discharge takes on all the characteristics of spring-water; it was found to be of interest to take note of the change of the composition of the water on those stretches of the course where it flows shows the ground. For this purpose it was necessary to take temperature-recordings, chemical examination of the water and a quantitative determination of the plankton. Samples were taken in 1954 of zooplankton at different times of the year at the discharge of the lake and analysed. The significant loss of organisms in the way of discharge is discussed.