356 Prodromus Systematis Nat. Regni Vegetabilis, $c. 



Primulaceae, by Duby ; — Asclepiadeae, by Decaisne ; — - 

 Gentianeae, by Grisebach ; — Polemoniaceae, by Bentham; — 

 and, Convolvulaceae, by Choisy. 



In the earlier volumes of the " Prodromus" both the 

 generic and the specific characters are very short, so much 

 so, that in such orders as contain many genera, and such 

 genera as contain a great number of species, the difficulty of 

 distinguishing between them often becomes very great. In 

 the late volumes, however, a great change was made for the 

 better in this respect. A still further improvement will be 

 found in the two last volumes, especially in those orders 

 which have been worked up by M. Alph. De Candolle him- 

 self, a short general character being added to the essential 

 specific one, To those who are daily occupied in deter- 

 mining species from descriptions, this renders the labour 

 comparatively easy. With how much greater facility, for 

 example, are the Apocyneae made out from M. Alph. 

 De Candolle's characters, than the Asclepiadeae from those 

 of Decaisne, where only essential characters are given. Only 

 one thing is now wanting to render the " Prodromus" the 

 most perfect systematic work which has ever been given to 

 the Botanical world, — a synopsis of the genera at the head 

 of each order. This would cost but little trouble to prepare, 

 would occupy but little space, and to working Botanists would 

 be a very great saving of time. 



The tenth volume may be expected about the end of the 

 present year, as we learn from Mr. Bentham, who is oc- 

 cupied with the Scrophularineae for it, that the printing was 

 to commence in January last. 



