144 b 



TPJUPJDACE.E. 



[Endogens. 



gemmules in a similar manner. This has been confirmed by the researches of Griffith, 

 showing that in Ambrosinia the embryo, at first quite homogeneous and entirely 

 cellular" throws out from different parts of its surface minute oblong cellular bodies, 

 which soon enlarge until they become five or six times the length of the original 

 nucleus, from which they finally detach themselves, assuming the form of a large 

 plumula.andservingasthegermsof future plants. This bears much analogy to the germi- 

 nation of Cerato] >hyl 1 um, which throws out an external series of processes, that have been 

 compared to a great number of cotyledons, while the still more numerous inner series 

 bears the semblance of a highly developed plumule. The leaves of this last-mentioned 

 genus appear destitute of nervures, and to consist only of confervoid parallel cells, 

 which divide themselves dichotomously into hair-like segments, thus denoting a lower 

 degree of development than has been assigned to it. The genus, too, has monoecious 

 flowers, with a simple perianth, with valvate aestivation, almost sessile anthers, an 

 unilocular carpel with a solitary ovule. ,,,„., ■, , 



" I have shown that the supposed facts upon which Mr. Gardner suggested the 

 relation of the Triuriace<c to the Menispermacea; and Smilaceaj, and of Sciaphila and 

 Hyalisma to the Urticacea?, are founded in error, and that their affinity towards the 

 Naiadaeese, which the structure of Triuris first suggested, is much confirmed by the 

 subsequent additions to our knowledge of the organisation of other genera of this 

 family. They agree with that order through Potamogeton in their inconspicuous c? £ 

 flowers, a perianth of four segments with valvate aestivation, several distinct carpels, 

 containing a single ovule, and seeds with a testaceous putamen containing a large 

 macropodous embryo. Some analogous points of structure in the fruit and seed of 

 Pistia have also been indicated by the same authority. 



" All the plants constituting this family have been found in intertropical South 

 America, Java, Ceylon, and the Philippine Islands, always in moist shady places, and 

 deriving their nourishment from the roots of trees. 



GENERA. 



Tribe TriurejE. 

 Triuris. Miers. 

 Iloxuris, Miers. 

 PeUophyUum, Gardn. 



Tribe Sciaphile^s. 

 Soridium, Miers. 

 Sciaphila, Bl. 



Ajihylhia, Champ. 

 Hyalisma, Champ. 



Numbers. Gen. 5. Sp. 8. 



Position. — Naiadaeese.- 



Ceratophyllacca:. 



-Triuridace^e.- 



Aracece." 



Alismaceao — Burmanniaceaj. 



The only observation that I would make upon the foregoing views is that what 

 Mr Miri-s (n-ms.-ui inenihryonal embryo 1 should rather call an exalbuminous embryo 



Kg. XCV. bis. 



SCV.W*— 1. Hexuris Gardneri ; S. its flower; 5. its carpel; 4. anther of Triuris hyalina 



