JMDMT #353 Microfossils of Cyanobacteria in Carbonaceous Meteorites
The James M. DuPont Meteorite Collection -in various European waters.- ' Size variants have been reported from different Swiss lakes: 92 ju in Lake Como, to 707 n in Lake Schwendi.-'' SampHng several ponds in the vicinity of Darmstadt, Germany at 2-week intervals over a 5-year period, Ljg|-29a found that population density fluctuated with rise and fall of tempera- ture. He noted seasonal variation in both horn length and horn number in C. hirundella. In the summer four-horned type, for example, horns were shorter during very hot summers than they were during cooler ones. Ap- parently, in fresh, as well as marine waters, horn development is an adaptive modification to resist sinking below optimal food and sunUt levels. Flaring, sail-like, structures from the girdle, inverted umbrella and parachute type membranes as in Ornithoceras, Diuophysis, and other forms'* ■-''
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