GEOGRAPHICAL DISTRIBUTION. 29 



in the Anti-Taurus; but both of these are merely borderers, just passing the 

 geographical boundary. 



There is also a remarkable break in the distribution of species at the Adriatic 

 and the longitude of Venice, three species only out of a total of sixty-nine, viz : 

 vermis, sativus and biflorus, and possibly also longiflorus, being common to the districts 

 east and west of the Adriatic. The district west of the Adriatic possesses twenty 

 species, sixteen or seventeen of which do not extend further east ; and the district 

 east of the Adriatic possesses fifty-three species, forty-nine or fifty of which do 

 not occur to the west of the Adriatic. 



Nearly the whole of the species occupy continuous areas, and with the exception 

 of C. vermis there is no instance of repeated occurrence in isolated districts separated 

 by wide breaks. C. vermis has a range of about 27° of longitude, from the Carpathians 

 to the Pyrenees; and the continuity of its range is somewhat broken in Central 

 France. C. biflorits has a wider range of longitude than any other species extending 

 for 40° from Italy into Georgia, and Persia; and the next in order of wide distribution 

 is C. sativus in its various forms, extending through 30° of longitude from Italy to 

 Kurdistan, and its distribution is essentialy oriental. The same may be said of 

 the annulate species, which have only one representative, C. bifiorus, as far west 

 as Italy. 



Of the division Involucrati, there are about thirteen vernal, and seventeen 

 autumnal species; and of the Nudiflori, thirty are vernal, and eight autumnal. 

 The orange species all occur east of the Adriatic; of the thirty species of Involucrati, 

 about half occur to the east and half to the west of the Adriatic; and the Nudiflori, 

 with two or three exceptions, are all limited to the region east of the Adriatic. 



The genus is remarkable for the wide ranging in altitude of the majority of 

 species, those that are essentially alpine or lowland being comparatively few in 

 number; and I believe there is no single species of the genus that is not perfectly 

 hardy, and capable of enduring any of the extremes of frost and heat of our climate. 



Geographical distribution in relation to Natural Affinity.- — The grouping geograph- 

 ically of allied species is not general, and the only two notable exceptions present 

 themselves in Western Europe and in Italy. 



In the Western European and North African district "A" there are six or 

 seven autumnal species; viz: C. nudijlorus, C. granatensis, C. astuneus, C. serotinus, 

 C. Salzmanni, and C. Clusii, all closely allied and forming a compact group; they 

 are all limited to Western Europe and N. Africa, where there are no other autumnal 

 species. Two out of the three vernal species, viz:— C. car/etamis, and C. 

 nevadensis, are also endemic, and are closely allied in their singular leaf-structure; 

 so that with the exception of C. vermis, which is sparingly transgressive from the 

 Alps, the whole of the West European and N. African species are not only endemic, 



