A PAGE OF FIGURES. 347 



The following is an estimate of the known species of plants 

 on the globe at different dates : 



Phanerogams. Cryptogams. Total. 



According to Linnaeus, 1753, 5,323 615 5,93$ 



Pusoon, 1807, 19,949 6,000 25,949 



Stendel, 1824, 39> 68 4 io>7 6 5 50,649 



Stendel, 1841, 78,000 13,000 91,000 



Stendel, 1844, 80,000 15,000 9S,ooo 



The advance made of late years in the knowledge of existing 

 species will be apparent from a consideration of Lindley's 

 estimate in 1846 : 



Genera. Species. 



Thallogens, ... 939 8,394 



Acrogens, , . , 310 4,086 



Rhizogens, . . . ' 21 53 



Endogens, . . . 1,420 13,684 



Dictyogens, ... 17 268 



Gymnogens, . . . 37 210 



Exogens, . . . 6,191 16,225 



Total, 8,935 9 2 >92O 



According to Hinds, the following families are almost en- 

 tirely restricted to particular divisions of the globe : 



To Europe Globulariaceae, Ceratophyllaceae. 



To Asia Dipterocarpaceae, Aquilariaceae, Camelliaceae, 

 Moringaceae, Stilaginaceae. 



To Africa Bmniaceae, Brexiaceae, Belvisiacese, Penaeaceae. 



To North America Sarraceniacese. 



To South America Rhizobolaceas, Gillesiaceae, Calycer- 

 aceae, Vochysiaceae, Simarubaceae, Monimiaceae, Hu- 

 miriaceae, Papayaceae, Gesneraceae, Lacistemaceae. 



