13 INIr. R. B. Hinds on Geographic Botamj. 



information, must account to us for not above a thousand differ- 

 ent species being recorded. The ancients at the same time were 

 not remiss in availing themselves of the properties of plants in 

 the healing art, or for domestic purposes. To some extent the 

 amount of known plants is an index of the advancement of the 

 science, and on examination this will be found to have proceeded 

 most irregularly ; indeed none worthy of attention was made till 

 the time of Linnaeus . Subsequently a rapid advance took place, 

 gradually increasing to the present time, when the progress out- 

 strips all precedent. 



Wliilst the first naturalists were recording such plants as their 

 exertions brought before their notice, none appear to have 

 hazarded an opinion on the total amount of the vegetation of the 

 world, till Hay ventured to fix it at 18,000. Though this amount 

 may seem small, it most probably appeared at the time it was 

 first promulgated of a more astonishing magnitude than the great 

 amount to be presently mentioned, as in om- opinion likely to be 

 an approximation to the total flora of the earth, will to us in the 

 present day. In the following details the first column expresses 

 the amount known to or noticed by each authority, and the second 

 column the total number of species which were, at the time spe- 

 cified, considered as existing on the globe : — 



Supposed 

 Known. Total. 

 A.c. 300 Theophrastus, History of Plants . 500 



A.D. 70 Pliny, History of the World . 1000 

 1580 Dodonseus, Stirpium Historia . 1330 



1623 Bauhm, Pinax 6000 



1690 Ray 18,000 



Tournefort 6000 



1753 Linngeus, Species Plantarum, 1st ed. 7300 

 1762 „ „ „ 2nded. 8800 



1796 Gmelin, Systema Vegetabilium . 16,635 

 1806 Persoon, Enchu-idium .... 27,000 



Humboldt 44,000 



1814 Brown, Fhnders' Voyage . . . 37,000 



1820 DeCandoUe, Theorie Elementaire 50,000 100,000 



1824 „ Prodromus . . . 50,000 



1827 Sprengel 37,000 



1830 Balbi, Geographic 80,000 



1835 Lindley, Introduction to Botany . 86,000 



Perhaps no botanist ever conducted his researches on any class 

 of plants without discovering that their amount exceeded all his 

 expectations. This was particularly the case with ourselves when 

 attempting to estimate the number of species spread over the 

 world. As a foundation for these speculations, I took the num- 



