72 



MAllSILEACE.E. 



[AOUOGENS. 



poUen "' collect about the nipple at the surface of the water, after which the " ovules" 



i,ll to the bottom, where, at the end of seven or eight days germination commences. 

 observations, however, require to be repeated: for Braun {Flora, 1839, p. 297,) 



and Griffith each regards both sorts of bodies as sporules. Fabre's experiment calls to 



mind those of Professor Savi of Pisa, upon Salvinia, 

 another plant of this Order. He put into different ves- 

 sels, 1st, the seeds alone ; 2d, the male globules alone ; 

 and 3d, both mixed. In the first two vessels nothing ap- 

 ]i ared ; in the 3d, the seeds rose to the surface of the 

 water and fully developed. But Duverney lias since 

 published a dissertation upon this plant, in which he 

 states that, having repeated the experiments of Savi, he 

 b:is not obtained the same results, and that the seeds, 

 when separated from the supposed male organs, developed 

 perfectly. 



The structure of Pi- 

 lularia is analogous. 

 From the very correct 

 and careful observa- 

 tions of Valentine, 

 (Linn.Trmis. 18.483,) 

 it has apparently been 

 proved, that the so- 

 called anthers of that 

 plant are, as I for- 

 merly suggested, no- 

 thing but abortive spores. 



Polio ring Jussieu, Salvinia and Azolla were sepa- 



rated in the last edition of this work as a distinct 



Natural < >rder, a view that Endlicher has since taken. 



Hut upon a full consideration of the structure of these 



plants, or of what is known of it, it does not appear 



to justify the separation. Like Pilularia and Marsilea, 



they have two distinct kinds of reproductive bodies 



enclosed in involucres, and that seems to be the main 



feature by which IVpperworts are known as an Order 



from Lycopodiaceee. For the same reason it appears 



better to combine with them Isoetes, instead of re.. 



carding that too as the type of still another Order. 



Mr. Griffith docs not include Isoetes among these 



plants , but I cannot assent to the propriety of erect- 

 ing every genua in this curious Order into a Suborder. 

 The genera Salvinia and Azolla have been the sub- 

 ject of sonic elaborate observations by Mr. Griffith, 



{Calcutta Journal, vol. v.), who elevates each into a 



Suborder, and throws an entirely new light upon 



their structure He regards them as having true 



sexes, the male being certain necklace-shaped threads 



found at an early stage, in contact with what he de- 



nominateaan orthotropoua ovulum. But strange to 



say, this so called ovulum, instead of giving birth to 



an embryo, becomes the parent of reproductive bodies 



of two totally different kinds, haying not even the smallest resemblance the one to the 



other, althon,!, the matrix out o. which they are evolved is identical at an early period 



of the organisation. I regret that Mr. Griffith's most curious memoir only reached me 



ill, Zt\ T SSfT^i ^"'f lt ^ im P° ssib le to have cuts prepared to 



.1 st rata hs observatums, foi winch the reader is referred to the work above ouoted. 



11 can do ia to give >n a note the substance of his descriptions of Salvinia and 



*' ertMUata.— Male organs ? articulated hairs on Hip «taii« „* «.„ _ i ^-i 



tolDtng a nucleus and a brownish fluid : Ovulanearly sea "L !»**£?£ 1 the °. vuIa : , ench , oint con ; 



■^ » t! '° 1| e, concealed by the roots, and partly covered 



W ,,,,„«„„, [,, diltont U. „tg,mtaallo ai ,d»«n.i„ s fro m 1. It, ,p.,«, ,,„ to . 



nag 



and 



