410 M. Duchartre on the Anatomy and Organogeny 



Plant, n. 323) state that the plant has " propagmes cyhndricpc ;" 

 but Tenore, observing more accurately, ascribes to it " sm'culi tu- 

 beriformes, in quibvis folia basi in niembranani dilatata, qure in 

 caule fiorifero basi soluta." (Syll. 288.) 



DeCandolle {oj). cit.) likewise mentions this difference in the 

 leaves, which is also exhibited in the above-mentioned figure, and 

 he states with reference to it, that " on est conduit a penser que 

 le petit appendice qu'on observe a la base des feuilles est une 

 espece de rudiment de la gaine des feuilles." [Lac. cit. p. 35.) 

 However, this formation of aerial tubers, if we may so express our- 

 selves, seemed to deserve closer attention, for no similar forma- 

 tion has hitherto occurred to me, or been observed to my know- 

 ledge, at least in Dicotyledons. 



I will lastly observe, that Sedwn amplexicaule differs from the 

 other species of this genus, not only in the number of pistils 

 and in the mode of reproduction, but likewise by the structure of 

 its cal}^, each sepal being externally considerably excavated, while 

 a prominent angle reaches from each sinus to the base, gi\'ing 

 the calyx a septangular or octangular appearance. These cha- 

 racters deserve to be recommended to some manufacturer of 

 genera for the creation of a nev\" genus. 



LX. — Anatomical and Organogenical Researches on Lathrsea 

 elandestina. By M. Duchartre *. 



The complete history of a plant from its origin at the period of 

 germination to the moment when, after having given birth to 

 new seed, it has accomplished all the phases of its existence, is 

 still wanting in botany ; for the type studied minutely in all its 

 details, in an anatomical and physiological point of view, which 

 man furnishes to zoology, does not exist in the vegetable king- 

 dom ; numerous materials, it is true, have been brought together 

 for the history of some plants, but there are none in which some 

 gap does not remain which it is essential to supply. 



The description of most plants is limited to that of theii' ex- 

 ternal forms ^dth respect to the organs of vegetation, and the or- 

 gans of reproduction have alone been examined generally with 

 more detail. Among the phanerogamous plants, the madder is 

 perhaps the only one which has been the object of an investi- 

 gation of this natui'e, profound and almost complete, due to ]M. 

 Decaisne. 



It would however be desirable, both for the interest of vege- 

 table anatomy in general and for the application of anatomical 



* Abstract of a Report laid before the French Academy by MM. de Mir- 

 bel, Richard, and Ad. Brongniart, April 28, 1S4.5. 



