WEDDELL'S MONOGRAPH OF URTICACEM. 89 



The reason why this mode of representation will exhibit 

 botanical affinities so well is, that (as we have elsewhere 

 remarked) the vegetable kingdom does not culminate, — as 

 the animal kingdom does, — and therefore offers no founda- 

 tion in nature for a lineal arrangement even of its great 

 groups. But it would appear that the Dicotyledonous orders 

 might be arranged under a considerable number of short 

 series, in groups converging upon the most fully developed or 

 representative order of each type, so as to exhibit what we 

 now know of the system of nature much better than in any 

 other way. 



We think that Dr. Weddell's idea of the affinity of Urti- 

 cacecB is a good one. The floral and seminal characters, the 

 true criteria of affinity, are not abhorrent, but present some 

 strong points of relationship, as do the organs of vegetation. 

 These, once established, allow us to feel the force of the strik- 

 ino- coincidence in the bast-tissue of the bark, so remarkable 

 in all this alliance for the length, fineness, and toughness of 

 the fibres, their union end to end, and their lateral indepen- 

 dence, admirably adapting them for their use as textile mate- 

 rials, in which Urticacece vie with Malvacem and Tiliacece. 



As to geographical distribution, Europe is very poor in 

 Urticacece, poorer even than would at first view be supposed, 

 as the author remarks. For as nettles like an enriched soil, 

 the five or six European species of Urtica and Parietaria so 

 abound around habitations that they make up in the multitude 

 of individuals for the paucity of species, and perhaps cover 

 nearly as much ground as the great number of intertropical 

 species ; two or three excepted, which are also weeds in the 

 tropics. Temperate North America is not much richer in 

 species than Europe. The greater part are found in the torrid 

 zone, and in islands rather than continents ; the Malay region, 

 India, Mexico, and the West Indies together possess almost 

 two thirds of the known species. 



Our remaining remarks shall be restricted to one well- 

 known plant described in the work, and to another of recent 

 discovery, which unfortunately was not communicated in sea- 

 son to find a place in it. 



