240 M. Duchartre on the Organogeny of the Malvaceae. 



XXIX. — Report on a memoir Z>y M. P. Duchartre, entitled ' Ob- 

 servations on the Organogeny of the Flower of the Malvaceae.^ 

 By MM. BiioNGNiART, Richard and De Jussieu*. 



We have been requested by the Academy to give an account of 

 the botanical memoir presented by M. Duchartre, and bearing 

 the above title. 



M. Duchartre has distinguished himself by various investiga- 

 tions, several of which have had the same object as the present, 

 but related to different plants ; many of them have been submitted 

 to the Academy and have received its approbation. These re- 

 searches may serve to explain several particular questions relating 

 to the vegetables to which they refer ; but in addition to their in- 

 terest in this point of view, they are of much greater importance 

 for the solution of general questions. We shall commence by 

 giving a sketch of them, and enunciating the problems to which 

 they relate, before detailing the results at which the author has 

 arrived in seeking for their solution. 



It is well known that botanists agree pretty generally in con- 

 sidering that the different parts of a flower represent so many 

 more or less modified leaves. These leaves, which constitute the 

 segments of the calyx and of the corolla, the stamens and the parts 

 of the pistil, are sometimes independent of each other as the true 

 leaves generally are, sometimes coherent by a portion of their 

 margins or their surfaces. DeCandolle, who has contributed so 

 much to the establishment of this theory, has proposed the word 

 soudure (confluence) to express this union, which implies that the 

 parts were primarily separate before being thus combined. How- 

 ever, he admitted that the separation could only have existed 

 prior to that period at which the parts become accessible to ob- 

 servation, and then this adhesion is called by him predisposed. 

 But that which he had not been able directly to establish, others 

 might anticipate doing, when the perfection of instruments and 

 methods of observation had removed the barrier by which he was 

 checked. This is, in fact, what has been accomplished. With 

 the aid of the microscope, the development of the organs has 

 been traced from their first appearance ; that is to say, from the 

 moment at which they separate from the axis to which they are 

 attached, and appear constituted simply by the aggregation of a 

 few cells. 



Now, are these primary rudiments constantly or only occa- 

 sionally independent of each other ? Upon this point observers 

 are not agreed. 



M. Schleiden speaks decidedly for the primitive independence 



* Translated from the Comptes Rendus for August 15, 1845. 



