194 REVIEWS. 



which is the very object of a good method. Indeed, when a 

 special organization is common to a large number of different 

 plants, it is evident that comparatively slight but constant 

 modifications of this structure ought to be particularly attended 

 to ; and this proposition seems to be especially true of the 

 JF*omacece." M. Decaisne puts foremost his strongest point 

 when he declares of the Quince, that " the nature of its bark 

 and wood, its prefoliation, inflorescence, the aestivation of the 

 corolla, the structure of the ovary and of the fruit differ es- 

 sentially from that of the Pears, among which certain bota- 

 nists still class it." Rather than combine the Quince and the 

 Japan Quince with Pyrus, we are confident that botanists 

 will generally accept his Docynia, along with Chanomeles 

 Lindl. and Cydonia, as independent genera. The same may 

 be said of Mespilus ; and it must be allowed that the charac- 

 ter which Kunth had noticed and which Decaisne has turned 

 to account, that of the deformation of one of the ovules which 

 becomes a kind of stipitate hood for the other, being common 

 to it and to Cratsegus, indicates a relationship to the latter 

 genus rather than to Pyrus. Much nicer and more question- 

 able characters are assigned to the genera here re-established 

 from Pyrus in the Candollean sense, to which we are in this 

 generation accustomed. These are, Aronia, Pers., our Choke- 

 berry (in which eight species are set up from what we take to 

 be a single polymorphous one) ; Sorbus, Tourn., the Mountain 

 Ash (the synonym S. microcarpa omitted from S. Americana^ 

 and S. samhucifolia is still taken to belong only to our west- 

 ern coast, whereas it extends across the continent) ; Aria, 

 Host., the Beam Trees, all of the Old World ; Torminaria, 

 Roem., for Pymis torminalis ; also Cormus, Spach, for Sor- 

 hus domestica^li., the Service-tree of Europe, with Fi/nis 

 trilohata, DC, and an allied species ; Micromeles, a new genus 

 for four Himalayan species thus far little known ; lastly, 

 Mains, Tourn. Here it is to be observed that M. divertilfoUa 

 is held to be distinct from M. rivularis ; and that a subgenus, 

 Chloromeles, proposed for 3f. atu/ustifolkt, our narrow-leaved 

 Crab-Apple, thus widely separated from 31. coronarhi., on 

 account, as is stated, of its reddish anthers and the structure 



