The chromosome numbers of 85 species of flowering plants from the Canary Islands were determined; 5 of the counts turned out to be new.Notes on some species are given. Numbers deviating from previous counts proved to occur in Polycarpaea divaricata (Pit.) Poir. and Koeleria phleoides (Viii.) Pers. 49 counts are new for the Canary Islands and are listed in table 2.

The chromosome number of 55 plant species collected in Southern France was determined.

Hybridization experiments were carried out with species of Geranium sect. Anemonifolia, sect. Lueida, sect. Pyrenaica and sect. Ruberta. All 9 species tested proved to be self-compatible. Of the 13 interspecific combinations tested only two were successful ( G. brutium X G. molle and G. purpureum × G. robertianum) but both hybrids were completely sterile. It is concluded that at least the European species are reproductively isolated and that hybridization experiments are of little value for an infrageneric classification of Geranium.

SUMMARY The chromosome numbers of 24 taxa of flowering plants of the southern U.S.S.R. were determined. Three counts were found to be new. Notes on some species are given.