572 



MARSILEACEiR, 



PI. CXXlV.f. I.,4. Contents of one of its secondaries. 



„ f. I.,5. Cross section of the same. 

 PI. CXXVI.f. I., a. Salvinia cucullata, natural size. 



All the figures, (with a few exceptions mentioned,) more or less 

 magnified: reduced for the most part from (measured) sketches 

 made under 1-lGth objectives of an achromatic microscope, by 

 Ross. 



ISOETES. 



Isoetes capsularis. 



pi. cxvi, cxvn, cxvm. 



Planta spithamsea pcdalisve axi brevissime inferne radicant. 

 caeterum covered, foliis rectis imbricatis, exterioribus oblique 

 ascendent, interioribus erectis, pagina anterior plana, dorso 

 convexissimo, ideoque quasi trigona, angulo postico rotun- 

 dato, intus dividuntur septis transversis crebris et cavitatibus 

 aeriis 4 longitudinalibus, margines basin versus in membrane 

 producuntur. 



Basis intus concava dilatat., fructigera. Fructus fere omni- 

 no inimersa dorso basi excepta, folio secus centrum adnato, 

 facei interna libera, (or a level with the surface of the leaf,) 

 quasi deliquescens demum folio lapso, liberofacto : parietes 

 antice tenuii, caeterum crassiusculi, cavitata septis longitudi- 

 nalibus divisa. 



[On examining Isoetes capsularis of Roxborough, which ap- 

 pears to be plentiful about Serampore I find, that botanist 

 appears to have adopted curiously incorrect ideas regarding the 

 structure of the genus. 



The functions of the male which I conjecture to be the 

 cordiform, oblong fleshy lamina about the female, from which 

 it is divided by an expansion of the leaf, probably analogous 

 to an indusium, appears to have been entirely over-looked. 



