Neuf espèces d’Hyménoptères parasites (Braconidae, Ichneumonidae) sont identifiées pour la première fois en Belgique: Atanycolus denigrator (Linnaeus 1758), Cosmophorus regius Niezabitowski 1910, Aleiodes dissector (Nees, 1834), Rhimphoctona pectoralis (Kriechbaumer, 1890), rufocoxalis (Clément, 1924), xoridiformis (Holmgren, 1860), Xorides alpestris (Habermehl, 1903), brachylabis 1889) et rufi...

Karyotypes are given for Boreonectes emmerichi (Falkenström, 1936) from its type locality at Kangding, China, and for B. alpestris (Dutton & Angus, 2007) from the St Gotthard and San Bernardino passes in the Swiss Alps. A phylogeny based on sequence data from a combination of mitochondrial and nuclear genes recovered western Palaearctic species of Boreonectes as monophyletic with strong support...

In early neurulae of Triturus alpestris the cranio-caudal distribution of differentiation tendencies in the presumptive prosencephalon was tested. Small grafts made from a median strip excised from the region of the neural plate and transverse neural fold were transplanted to a pocket made under the cranio-ventral ectoderm of early neurulae. Grafts made from the middle portion of the strip show...

Numerical analysis of the taxa belonging to the genus Rosularia (DC.) Stapf was carried out to find out their phenetic relationship. Data from different disciplines viz. general, pollen and seed morphology, chemistry and distribution pattern were used. As a result of cluster analysis two distinct groups are formed. Out of which one group consists of R. sedoides (Decne.) H. Ohba and R. alpestris...

If a causative virus can be demonstrated in mesenchymatous fowl tumors, either in those originating spontaneously4 or induced by chemical carcinogens,3 and if at least two other viruses are the probable causes of two epithelial tumors, one in the frog (R. pipsens)2 and the other in the Triton (7. alpestris),' it would obviously be interesting to ascertain whether viruses could be demonstrated i...

C E L L movement and migration seem to play an important role in the formation of tissue-patterns during embryogenesis. Phenomena such as the appearance of loosely attached cells in the mesoderm, or of the freely migrating neural crest cells, are quite common in embryonic development. Since the tissues of adult organs are mostly rather compact in structure it seems that the capacity of isolated...