1813.] Imperial Institute of France. 75 



respecting their growth, and respecting the structure, both 

 internal and external, of the organs of fecundation of plants. 



M. Henri de Cassini, son of one of our associates, a name so 

 celebrated in astronomy, has presented to the Class a memoir, 

 which augurs success in a different science. He has examined 

 with peculiar care the style and stigma in the whole family of 

 plants known by the name of compound, synsenesious, or syman- 

 therous; and these small organs have exhibited a number of 

 curious differences, which have induced him to propose a division 

 of these plants, founded solely on the modifications of these two 

 parts of the pistil. We regret that we cannot follow this skilful 

 observer in the details into which he has gone, and which he has 

 described and drawn with remarkable neatness. It cannot be 

 doubted but they will one day be of great service in perfecting 

 the classification of this family, so numerous and so natural ; the 

 .subdivision of which, in consequence, ought to be more difficult 

 than of any other. 



There are few families of vegetables so directly useful to man 

 as the grasses, which comprehend wheat, rye, rice, mais, sorgho, 

 sugar-cane, barley, oats, millet, &c. To name these plants is 

 enough to show the importance of a work which would enable us 

 to distinguish them with certainty. The characters hitherto 

 employed are generally regarded as insufficient. At each step 

 the observer finds himself stopped. It is difficult, indeed, often 

 impossible, to find the true genus of the plant which he examines. 

 Frequently the characters adopted only apply to a few species, 

 and do not occur in the rest of the genus. M. Palisot de Beauvois 

 has undertaken a general examination of this family, which he 

 has published under the name of Essai d'Agrostogropkie'. He 

 has endeavoured to put an end to all this confusion, and to givS 

 to each genus constant characters, easy to perceive, so that the 

 observer can never he at a loss. 



For this purpose he has been obliged to adopt new bases, 

 which he has already announced in his Flora of Oicurc and 

 Benin. These depend principally on the separation or union of 

 the sexes, on the composition of the flower, and on the number 

 of its envelopes. Twenty-five plates, in which all these cha- 

 racters arc represented, facilitate the study of these plants, which 

 inteicst all the orders of society, even those persons who do not 

 make botany a peculiar study. 



M. de Beauvois continues his Flora cTOware el de Benin, the 

 thirteenth number of which is published, and his History of 

 Instill collected in Africa and America, the eighth number of 

 which has appeared. 



M. de la Billardiere has finished his collection of the rare 

 plants of Syria and Libanus, by the fourth and fifth parts. The 



