70 



The geographical distribution of this genus is very general ; 

 it is not merely confined to the northern hemisphere, for I my- 

 self saw Ceratophylla in Chili *, and other travellers have also 

 observed them there. 



Dr. Schleiden admits only one species of Ceratophyllum) and 

 calls this C. vulgare ; a long series of observations are enume- 

 rated to prove this view. 



Asa Grayt has also recently written on the affinities of the 

 genus Ceratophyllum ; it appears to him that a great similarity 

 prevails between the embryos of the genera Ceratophyllum and 

 Nelumbium, which he endeavours specially to demonstrate, and 

 then places the Ceratophyllacece in the immediate vicinity of 

 the Cabombacece and Nelumbiacece. The memoir contains 

 no new observations, nor do I find anything respecting the 

 structure of the Ceratophyllacece. 



On the Propagation of Vegetables, and on the Organs that 

 contribute to it. 



Mr. Felix Dunal, of Montpellier J, has made us acquainted 

 with some interesting observations on the organs of fructifica- 

 tion of a Marsilea, which have been made by M. d 5 Esprit 

 Fabrewith great accuracy. The specific name of Fabrihas been 

 assigned to this Marsilea ; there can, however, be little doubt 

 as to its being the same species described byTenore as Marsilea 

 pubescens ; this latter name must consequently be retained ! 



The generative organs of this Marsilea are in some respects 

 of a different structure from those of our common Marsilea : 

 their functions are, however, more easily recognised than 

 in this. At the base of the petiole are situated the capsules, 

 each on the involute side of the termination of a conical 

 pointed pedicel, which is partly inclosed by the inferior mar- 

 gins of the two valves, forming the capsuliform involucrum 

 of the inflorescence or the organs of fructification : the in- 

 closed part therefore constitutes the receptacle, from which 

 proceed on both sides vascular bundles which surround all the 

 organs of fructification. As soon as the involucrum has opened, 



* Meyen's Reise, &c., i. p. 370. 



f Remarks on the structure and affinities of the order Ceratophyllacece. 

 Ann. of the Lyceum of Nat. Hist, of New York, 1837, iv. p. 41 . 



J Observations d' Esprit Fabre sur la structure, le de" veloppement, et les 

 organes generateurs d'une espece de Marsilea trouvee dans les environs 

 d'Agde. Ann. des Scien. Nat., Avril 1837, p. 22 l,avec planches xii. etxiii. 



