XXXV.—A Contribution to the Ornithology of the Libyan Desert.

The Libyan Desert is described and the specimens collected in the interior by British and Italian workers are listed. Among the otherwise very scanty resident population Falcons are surprisingly abundant. The evidence for migration across the desert is reviewed for each longitude. The Cyrenaican list of passage migrants closely resembles the Egyptian list without its eastern elements. I conclude that a broad-front migration of northern forms takes place at least from long. 21° to long. 31° (600 miles) and that a large proportion of all the birds travelling through N.E. Africa see nothing of the Nile. The new data for several individual forms are discussed, especially Storks and Shrikes.     

The serological grouping of Candida albicans strains isolated in the Kraków province in the years 1963–1965 by means of agar gel diffusion test

Summary One hundred forty sevenCandida albicans strains isolated from different clinical specimens were serologically differentiated. Agar gel diffusion test inBjörklund modification was applied inCandida albicans grouping. Autolysates prepared from the strains under study and from the group A and B standard strains ofHasenclever were used as antigens against anti-Candida albicans group A rabbit immune sera. Among 147 examined strains isolated from 107 patients, 137 strains were classified as belonging to group A and only 10 (9.3 %) strains as belonging to group B.     

Reproduction and perennation of Chondrilla juncea L. (skeleton weed) in the Western Australian wheatbelt

Survivorship of first-year plants of Chondrilla juncea was considerably higher on a deep yellow sand than on a yellow duplex soil. Mortality on the latter soil was associated with drying of the Al horizon during early summer. No plants produced seeds in their first year of growth on the duplex soil. However, during both years of the study, first-year individuals of both forms of C. juncea produced viable seeds when growing on the deep sand. Higher population growth rates could be expected on deep sands, owing to a combination of earlier reproduction and greater survivorship through the first summer. It is suggested that whilst the entire wheatbelt might be climatically suitable for C. juncea, the invasive potential of this weed might be restricted by edaphic characteristics over large areas.