One of the characteristic facies of the Permian Ratliegend desert deposits in NW Europe consists of interbedded adhesion-ripple and dune sands. This facies, present in an east-west oriented, wide belt in the south-central part of the north Sea, has been interpreted as coastal, in the sense of being adjacent to a large, saline, inland body of water. This facies, present in an east-west oriented, wide belt in the south-central part of the north Sea, has been interpreted as coastal, in the sense of being adjacent to a large, saline, inland body of water. The main object of this paper is to show that if these recent desert-sand deposits were accumulating in a subsiding area, eolian sequences similar to those of the Rotliegend would form; this applies both to the sedimentary structures and to the early cementation of the sands with evaporite minerals.
the sorption of water vapor by dead plant material under subsaturated conditions wass measured as a function of the realative humidity (RH). With prolonged exposure to high RH's the water content of the material may reach values in excess of 70%. Since the humidity in the Namid desert, at least near the coast, is almost always very high, the data suggests that absorbed water could be an important water source to debris-eating animals in this region.
Evidence that Welwitschia is able to absorb and translocate the water which condenses on its leaves under foggy conditions has been obtained by the application and subsequent localisation of tritiated water. Scanning electron microscopy of the leaves suggests that the path of water uptake may be via the stomata. Rates of uptake under foggy and fhn wind conditions are compared. Preliminary investigation of the movement of photosynthetic assimilates indicates that these are rapidly translocated in the direction of the meristematic regions.
The ecology of Aporosaura anchietae Bocage was descriptionbed by Louw and Holm (1971). In that paper it was i.a. pointed out that this lizard is strictly diurnal, ultrapsmmaphilous (Koch, 1961) and sand diving, that it is an opportunistic feeder on wind blown grass seeds and small arthropods, and has a Iarge storage capacity for food and water.
Though vultures may be practical and not very nice, they are a group of of South West Africa fascinating birds that have stirred the mind of man since ancient times. In spite of all the popular and scientific interest in birds, information on the natural history of vultures is still so scant that even modest chance observations in the field can yield new facts. Vultures include some of the largest of flying birds. By their keen senses they are able to locate carrion from afar and swiftly.
Althought tenebrionid beetles are probably the best studied insect group of the Namib Desert most of the studies have concerned themselves mainly with taxonomy and, more recently physiology, behaviour and ecology. No investigation known to date has endeavoured to establish if reproductive cycles exist, or to evalute the factors controlling time of reproduction of desert tenebrionids in their natural habitat. This study was undertaken as a first attempt to partially fill this important gap in the available information relating to these most interesting and extremely well-adapted desert insects.