TRANSACTIONS OF SECTION K, 917 



the 'Synopsis' of Persoon (1807), included as many as 20,000 species ofPhanerogams 

 alone. Turning now to the end of the century, we arrive at the following census, 

 for which I am indebted mainly to Professor Saccardo (189:i) and tu Professor 

 de Toni who has liiudly given me special information as to the Algse : — • 



Species of Phanerogams indicated in Benfham and Hooker's ' Genera 

 Flantarum ' [Durand, ' Index,' 1888). 



Dicotyledons 78,200 



Monocotyledons 19,600 



GymnosperrDS 2,420 



100,220 



Estimated subsequent additions (Saccardo) . . 5,011 

 Total Phanerogams . . 105,231 



Species of Ftcridophyta (indicated in Hooker and Baker's ' Si/nopsis ; ' 

 Baker's ' jS''eic Ferns ' and ' Fern Allies '). 



Filicina; (including Isoetes), about . . . 3,000 



Lycopodinas, about 432 



Equisetinfc, about 20 



Total Pteridophyta . . 3,452 



Species of Bnjophyta {Saccardu's Estimate). 



Musci 4,609 



Hepaticse 3,041 



Total Bryophyta . . . 7,650 



Species of Thallophyta. 



Fungi (including Bacteria) (Saccardo) . . . 39,663 



Lichens (Saccardo) 5,600 



Alga3 (incl. 6,000 Diatoms) (de Toni) .... 14,000 



Total Thallophyta . . . 59,263 



Adding these totals together — 



Phanerogams 105,231 



Pteridophyta 3,452 



Bryophyta 7,6.^0 



Thaliophjta 59,263 



we have a grand total of 175,596 



jaa the approximate number of recognised species of living plants. 



These hgiires are sufficiently accurate to show how vast have been the additions 

 to the knowledge of plants in the period under consideration, and they afford much 

 food for thought. In the first place, they indicate how closely connected has been 

 the growth of this branch of Botany with the exploration and opening up of new 

 countries which has been so characteristic a feature of the century. Again, no one 

 can consider these figures without being struck by the disparity in the numbers of 

 species included in the different groups ; a most interesting topic, which cannot, 

 however, be entered upon here. It must suffice to point out in a general way that 

 the smaller groups represent families of plants which attained their numerical 

 zenith in long past geological periods, and are now decadent, whilst the existing 

 flora of the world is characterised by the preponderating Angiosperms and Fungi. 



