3oS Analysis of the Labours of the Royal Academy 



are these laws, that whenever we know the number in any country 

 of the species of one of those families of which M. Humboldt has 

 given a table, we may flediice from it a pretty exact calculation 

 both of the total number of vegetables and of the number of 

 species in each of the other families. 



The Prolegomnna to which we allude are placed at the head 

 of the great work which M. Humboldt is at present publishing 

 with Messrs. Bonpland and Kunth, upon the new plants which 

 he has discovered in equinoctial America. This addition, the 

 richest and most brilliant perhaps which botany has received at 

 one time, will appear in six volumes quarto, and contain six hun- 

 dred plates and the description of more than four thousand species. 

 The first volume, including all the monocotyledones, has been 

 published this year : it presents us with tliirty-three new genera, 

 and among the palm<v alone twenty-three new species, Messrs. 

 Piumboldt and Donpland have published at the same time the 

 conclusion of their description of the ISlelnslovia, a work of most 

 magnificent exterior, but which could not be imitated throughout 

 tije whole range of vegetables, without incurring an expense and 

 delav as prejudicial to science as to its cultivators. 



^I. de Beauvois, whose perseverance is also deserving of every 

 praise, has pulxlished this year the fourteenth and fifteenth parts 

 of his Flore d'Oware el de Benin; and, not satisfied with his 

 ancient collections, he has taken advantage of the extraordinary 

 humidity of this year to pursue his investigation into the class of 

 Fungi. The continual rains have so developed this class, that 

 he has discovered many species which iiave escaped precedhig 

 botanists. Such are — a variety of sclerotiam which has lessened 

 nearly by two-thirds the crop of kidney beans, upon which ic 

 propagates itself; — a new species ofspkeria, which has been very 

 destructive to onions; also a new species oi cereda, which has 

 been still more pernicious to them ; and lastly, which is very 

 remarkable, a ::ew genus of parasitic plant which grows upou 

 other parasite?, and injures very considerably the vegetables 

 which are obliged to nniirish both. 



The family of the dlpsncci, such as the scabious, are, it is well 

 known, very nearly allied to composites by many of the cha- 

 racters of their flowers and tlieir fruits; — the most apparent 

 mark which distinguishes them is, that the anthers are entirely 

 free. Botanists have di;;covcred ^ome plants whose flowers are 

 equally formed of many fmaller flowers, tl^e anthers of which are 

 united at the bottom only. It haf. been found doubtful what 

 place to assign them. M. Henri de Cassini, who has examined 

 them at the close of his great work on the class oiSyvgcnesia or 

 ComposiliP, has found that they differ from thee — becaTise their 

 autherSi are not united at the top, because tlieir style and ctigma 



are 



