ANNOTATIONS AND ADDITIONS. 293 



candolle in France 3645 species of phsenogamous plants. I would also 

 recall that even now new Genera (some even consisting of tall 

 forest trees), are being discovered in the small West Indian Islands 

 which have been visited by Europeans for three centuries, and in 

 the vicinity of large commercial towns. These considerations, which 

 I propose to develop in further detail at the close of the present 

 annotation, make it probable that the actual number of species 

 exceeds that spoken of in the old myth of the Zend-Avesta, which 

 says that " the Primeval Creating Power called forth from the blood 

 of the sacred bull 120,000 different forms of plants!" 



If, then, we cannot look for any direct scientific solution of the 

 question of how many forms of the vegetable kingdom including 

 leafless Cryptogamia (water Algae, funguses, and lichens), Characese, 

 liver-worts, mosses, Marsilacese, Lycopodiaceae, and ferns exist on 

 the dry land and in the ocean, in the present state of the organic 

 life of our globe, we may yet attempt an approximate method by 

 which we may find some probable "lowest limits" or numerical 

 minima. Since 1815, I have sought, in arithmetical considerations 

 relating to the geography of plants, to examine first the ratios which 

 the number of species in the different natural families bear to the 

 entire mass of the phsenogamous vegetation in countries where the 

 latter is sufficiently well known. Robert Brown, the greatest 

 botanist among our cotemporaries, had previously determined the 

 numerical proportions of the leading divisions of the vegetable 

 kingdom; of Acotyledons (Agamae, Cryptogamic or cellular plants) 

 to Cotyledons (Phanerogamic or vascular plants), and of Mono- 

 cotyledonous (Endogenous) to Dicotyledonous (Exogenous) plants. 

 He finds the ratio of Monocotyledons to Dicotyledons in the tro- 

 . pical zone as 1 : 5, and in the cold zones of the parallels of 60 N. 

 and 55 S. latitude, as 1 : 2j. (Robert Brown, General Remarks 

 on the Botany of Terra .Australis, in Flinders' Voyage, vol. ii. p. 

 338.) The absolute number of species in the three leading divisions 

 of the vegetable kingdom are compared together in that work 

 according to the method there laid down. I was the first to pass 

 from these leading divisions to the divisions of the several families, 

 and to consider the ratio which the number of species of each family 

 bears to the entire mass of phsenogamous plants belonging to a zone 



25* 



