414 M. Duchartre on Lathrsea clandestina. 



which would thus differ from that stated by Mr. Bowman in 

 Lathrcca squamaria. 



The majority of the plants parasitical on roots are destitute of 

 true leaves, these organs being reduced to short scales which 

 seem to correspond only at the base of the petioles ; this is seen 

 in the Orohanchce, Monotropa, and several exotic plants which 

 present the same mode of growth^ and these reduced and abortive 

 leaves appear^ as well as the stems, generally destitute of those 

 epidermal pores designated by the name of stomata. 



The appendicular organs of the Lath^aa present a very differ- 

 ent form and structure, although short and imbricated like scales ; 

 they are narrowed at their base into a sort of petiole, and present 

 a true cordiform fleshy limb, analogous to that of the leaves of 

 certain succulent plants. Mr. Bowman had already indicated 

 the large regular gaps which traverse the interior of these kinds 

 of leaves, but he believed these organs to be destitute of stomata, 

 and it was not till within a few years that Dr. Schleiden noticed 

 the existence of these pores on the leaves of Lathraa squamaria. 

 M. Duchartre had discovered these organs, not only on the cu- 

 ticle of the leaves, but on that of the stems of the L. clandestina, 

 and at a period when he could not know of the observation of 

 Dr. Schleiden, and had insisted on this exception to a character 

 considered as general among the plants parasitical on roots. 



His memoir contains, moreover, a very complete anatomical 

 description of these rudimentary but complicated leaves, of their 

 nerves, of their parenchyma and of the empty spaces which regu- 

 larly occur in them, and of the papillae which clothe them ; finally, 

 the mode of evolution of these organs is carefully followed out, 

 and it is one of the most complete chapters of the history of this 

 remarkable plant. 



With respect to the organs of reproduction, the plant which 

 was the object of the examination of M. Duchartre did not pre- 

 sent any singularity which might lead us to presume anything 

 very peculiar in their structure ; but, as we have said at the com- 

 mencement of this Keport, a complete anatomical description of 

 the different organs of a vegetable is still a thing so rare as to 

 offer considerable vitility to science by the means of comparison 

 which it permits of our establishing at a later period. 



In this point of view, the anatomical investigation of almost 

 all the parts of the flower of L. clandestina, such as M. Duchartre 

 has given, deserves great praise ; but the author has moreover 

 du'ected his attention in a special manner to the mode of deve- 

 lopment of the different floral verticils. Thus the mode of ap- 

 pearance of the calyx, the corolla, the stamina and the pistil, the 

 changes which take place in the anthers and the ovary have been 



