3^8 Imperial Institute of Trance, 



merous an^ so natural, and the subdivision of which ought 

 con«equentlv to be more difficuh than anv other. 



There are few families of vegetables so directly useful to 

 man as thn of the grasses, among which we reckon oats, 

 barley, \\hcat, rice, n)aize, the sugar cane, hay, Sec. &:c. 

 The bare mention of the name of these plants is suffi- 

 cient to show the importance of any work which shall de- 

 scril>e them with accuracy. 



The characters hitherto have been generally regarded as 

 insufficient. At every step the ol)servcr is arrested : and 

 it is difficult, nav, often impossible to discover the true 

 genus of the plant under examinaiion : frequently also, the 

 characters adopted aQ;ree with certain species only, and are 

 no longer recovered in the rest of the genus. 



M. Palifot de Beauvois has undertaken on the subject? 

 of this f.iniilv a general work which he has entitled, An 

 Essay upon Agrostography. He has endeavoured to remove 

 all confusion, and to give to each genus signs which are 

 constant and easily discovered, so that no observer can be 

 mistaken. 



With this view he has been obliged to adopt new bases, 

 which he has alreadv announced in his Flora of Oware and 

 £enin, and which chiefly belong to the separation or junc- 

 tion of the sexes to ihi? composition of the flower and the 

 number of its envelopes. 



Twenty-five plates, in which all these characters are re- 

 presented, facilitate the study of these plants which in- 

 terest all classes of society, and even those who do not 

 study botany as a science. 



M. Beauvois continues his Flora of Oware and Benin, the 

 thirteenth number of which is published ; and his History 

 of Insects, collected in Africa and America, the eighth 

 number of which has appeared. 



M. de la Billardiere has continued and finished the col- 

 lection of his rare plants of Syria and Liban, by the publi- 

 cation of the fourth and fifth numbers. 



The same naturalist has communicated to the Class se- 

 veral interesting observations in natural history which he 

 made in his vo'-age to the Levant, the publication of which 

 V as interrupted bv the longer and more dangerous voyage 

 which he since undertook along with d'Entrecasteaux, and 

 the account of which has been before the public these many 

 years. 



M. Gouan, corresponding member of the Class at 

 Montpelier, has published a description of the generic cha- 

 racters of the ginko-biloba, a singular tree of Japan, which 



had 



