zoology

About 235 species of orchid bees (Euglossini) inhabit the rainforests of Central and South America. Of the five identified genera, three are nest building and two are brood parasites. They are distinctive amongst the bees for three unusual features: they have extremely long tongues; many species gleam with iridescent colours and the males of… read more

The upright position in the evolution: ‘Why is the fluke of the Whale shaped horizontally?’

Dolphins and whales are water-based mammals and differ in various characteristics from fish, the predominant water species. A comparison of those two animal groups provides helpful insights into basic concepts of evolution. Evolutionary research… read more

It has long been regarded as unscientific to consider the musical aspects of territorial behaviour among songbirds. The musical abilities of song birds, for example their perception of melody and their capacity to transpose, have been questioned many times. Furthermore, avian intelligence — With the exception of ravens and parrots — was… read more

Miniatures on the path. Two red algae in freshwater, two swallowtail butterflies, and two amphibians in comparison

Both native freshwater red algae, Batrac/oospermum and Lemanea, have been introduced. Their morphology in space and time are compared. A report on breeding both native swallowtail butterfly species - Ipbiclides podalirius… read more

An outline for a biology of freedom using songbirds as an example - Concerning the differentiation of the territorial song

The territory defended by songbirds is much more an acoustic territory than a foraging one. Therefore singing outside a territory more often leads to conflict than does searching for food there. The great… read more

The egg shell structures of reptiles as a picture of the animal's constitution

The articles on bird egg shells in the Tycho de Brahe yearbooks 1996 and 1997 are here supplemented with an article on reptile eggs which also reviews the situation with the birds.

The poikilothermic reptiles mostly bury their predominantly colour… read more

On the threefoldness of beetles

Beetles are regarded in their systematic relationships as a superorganism. Concerning their evolutionary differentiation, is there any relation between the different organ-systems most animals have and the different beetle families, genera or species? Proceeding from a threefold analysis of highly… read more

Cephalopods, snails and bivalves in their organismic relationship

This contribution was first published in 1973 by Thomas Göbel after mutual discussions on the subject. It is reprinted here enlarged and supported by further details. The main point is to demonstrate how the molluscs can also show the scientific fruitfulness of a… read more

The tunicates - aspects of their threefoldness

The concept of threefoldness (sense-nerve system, metabolic system, rhythmic system) is applied to the hermaphroditic tunicates with their classes Appendicularia, Thaliacea, and Ascidia.

Ascidians are sessile organisms with a tadpole-like free-swimming larvae but often with a purely… read more