on the Geography/ of Plants. 237 



2. Ejusdem sur les lots que Von observe dans la distribution des 

 formes Vcge tales. Paris, 1816. 



Read in the Institute of France, 29th January 1816. 



In the treatise which I have marked No. 1., the Author con- 

 siders chiefly the following objects : — 1 . The whole number of 

 hitherto known plants, and their distribution in the different 

 parts of the world. 2. The distribution, in regard to climate, 

 of some of the most important families. 3. The distinction be- 

 tween the social and solitary occurrence of plants. 4. Whether 

 the same plants are found in both great continents, and to what 

 extent. 5. The comparison of temperature in the old and new 

 worlds in different latitudes. 6. The influence of altitude upon 

 vegetation in the different zones; and lastly (7), he gives us an 

 essay on the determination of the climate that is best adapted 

 to any of the most important cultivated plants ; and in tlie work 

 itself, to which No. 1. forms the introduction, the families are 

 generally followed by a geographical view of the same. The 

 treatise which I have marked No. 2. cannot properly be con- 

 sidered as any thing more than an abridgment of No. 1. But, 

 before I enter upon the proposed examination, I wish to offer a 

 few observations upon what the author says, in a note p. xii., 

 upon the science of the geography of plants. 



If he, by the following: " Geographia plantarujn vincula et 

 cognationem tradit, quibus omnia vegetabilia inter se comiega 

 sintf terrcB tractus quos teneant, in ajtrem atmospkcericum quce sit 

 eorum vis ostendit, saxa atque rupes quibus potissimum algarum 

 primordits radicibusque destruanfur docet, et quo pacto in telluris 

 tuperficie humus nascatur, commemorat*/' intends to give a defi- 

 nition of the geography of plants, one cannot by any means ap- 

 prove of this view of the subject ; because, being merely an 

 enumeration of the chief points which constitute the science, 

 no advantage is gained by it. The examination of the natural 

 affinities between plants, or, in other words, the natural ar- 



» This is taken literally from his earlier work, entitled Specimen Flone 

 Fribergensis. Beroiiui* 1793. p. Ix. Note. 



