MARSILEA. 



499 



It is a much more developed plant than Salvinia or Azolla, 

 the most remarkable difference it presents from Ferns, are the 

 partial vernation, the termination of the veins, and pseudo 

 male organs, ovaria of authors, also the separation and situa- 

 tion of the sori, the quaternation of the fronds, and anatomy 

 in general. 



II. MARSILEA. 



General Remarks. 



Nothing like sexes in Marsilea. 



Reproductive organs always extra axillary. 



Each capsule represents a carpellary leaf. 



The first appearance of the organs is uniform, in rows, at 

 right angles with the midrib, unchanged spaces being left be- 

 tween them, in which spaces appearances occur as if there 

 would be vessels. 



Of these bodies which are entirely cellular and opaque, as if 

 from contained air, some are larger than others, and the larger 

 arc confined to the central line of each set. The two kinds, 

 though subsequently so different are not distinguishable at 

 such periods, both being cellular and grumous, but some are 

 larger and sessile by a broad base, these may afterwards be- 

 come the sessile rcproductives. 



x\t the earliest period, the capsule is mucilagino-cellular, with 

 a flat front face, along the centre of which is a depression in- 

 dicating the line of folding ?. At this period they are solid. 

 The tissue along this central depression, appears if I may so 

 say, thrown off subsequently, the margins of inflection, (so far 

 at least as the cavities containing the reproductives are con- 

 cerned,) being formed on either side of it. Can it be analogous 

 to the male of Isoetes, which would have a somewhat similar 

 dispostion if the leaf were folded on itself. 



The usually supposed male organs are subovate, or subob- 

 ovate in form, they consist, when mature of an outer cellular 

 lax coat, an inner ditto, which when immersed, expands and 



