Thirty-four chromosome counts are reported from populations in 20 species from Masafuera in the Juan Fernandez Islands, Chile. New species counts are in Abrotanella crassipes (2n = 18), Carpobrotus aequilaterus (n = 9), Coprosma pyrifolia (n = 22), Drimys confertifolia (n = ca. 43), Euphrasia Jormosissima (n = 44), Parietaria debilis (n = 8), and UrticaJernandeziana (n = ca. 11). A new chromoso...

Chromosome counts of Asteraceae are reported from Mexico, the United States, the West Indies, Peru, and Bolivia. First counts are reported for 27 species, eight infraspecific taxa, and three interspecific hybrids in Brickellia, Chrysanthellum, Cirsium, Egletes, Erigeron, Flaveria, Gnaphalium, Heterotheca, Hieracium, Hymenothrix, Koanophyllon, Layia, Lessingia, Pectis, Sclerocarpus, Stuessya, Ta...

Twelve tundra swans, Cygnus columbianus (Ord), from Nevada and one from New Mexico were collected and examined for schistosomes. Mature worms, determined as Allobilharzia visceralis, were found in 92% of the swans, in the inferior mesenteric vein of the large intestine and its branches. In 12 cases, there was endophlebitis of the inferior mesenteric vein. The morphology of the worms is consiste...

Eight digenetic trematode species (Phylum Platyhelminthes, Subclass Digena), one cestode species (Phylum Platyhelminthes, Class Cestoidea) and three nematode species (Phylum Nematoda) were recovered from the little brown bat, Motis lucifu us, at the Neda Mine hibernacu1um in southeastern Wisconsin. Bats displayed a rich and diverse helminth fauna throu~hout the year. Statistically significant s...

Treatment with the antitubulin vinblastine was found to disrupt the spindle system in dividing root-tip cells of common wheat, Triticum aestiuum L. Genotypes lacking the somatic association suppressor gene on 5BL, or containing the somatic-association promoter on 5BS, were found to be more sensitive to the treatment. In genetic lines carrying the somatic association suppressor, sensitivity to v...

Wallinia chavarriae n. sp. is described from the small-bodied characids Astyanax aeneus and Bryconamericus scleroparius in the Area de Conservacion Guanacaste, northwestern Costa Rica. The species differs from W. valenciae in possessing an acetabulum that is smaller than the oral sucker and vitelline follicles that are ovoid or rounded rather than elongate and tubular. Detailed comparison betwe...

The Paramecium tetraurelia mutant called d48 has a complete copy of the A surface protein gene in its micronuclei, but lacks the A gene in the macronucleus. Previous experiments have shown that microinjection of a plasmid containing the entire A gene or a large portion of the gene into the macronucleus of d48 rescued the cell line after formation of a new macronucleus (autogamy). Here we show t...

TENORA, F., BARUš, V., PROKEš, M.: Discussion to several tapeworm species from the families Hymenolepididae, Anoplocephalidae and Davaineidae parasitizing rodents and man. Acta univ. agric. et silvic. Mendel. Brun., 2004, LII, No. 1, pp. 23-28 With the more recent knowledge, the hypothesis by Joyeux and Baer (1929) is consulted: “... most of rarer species of tapeworms occurring in man are proba...

Germination of Oncwk seblis L. spores is controlied by light and temperature. Temperatures of30 C can induce maximal germination in the dark to a level of 60 to 95% of that induced by a saturating dose of red light (0.38 joules/square meter) providing the spores are placed at the elevated temperature immediately after being sown. Maximum dark germination occurs with a minhmum exposure of 16 to ...

In the present investigation cytotoxic and chromotoxic effects of crude extract of bottle gourd was evaluated by employing Vicia faba root meristem assay. Roots of Vicia faba were treated with 100, 250 and 500 g/L solution of crude extract at room temperature in dark for 6, 12, 18 and 24 h. Cytotoxicity and chromotoxicity were expressed in terms of depression in mitotic activity and frequency o...