72 Mr. KiPPisT on the existence of Spiral Cells 



often present a peculiar chain-like appearance, from their being contracted at 

 short intervals, and apparently compressed in opposite directions. In tv/o 

 species of Goldfussia, G. divaricata and G. lamiijlora, they are very long and 

 slender, but distinctly jointed or annular. Those of G. pentstemonoides and 

 G. colorata are often singularly refracted and waved at their extremities. 



Hairs of a very remarkable form occur on the seeds of two closely-allied 

 Chilian plants, one of them being the Ruellia dulcis of Cavanilles, the other a 

 new species found at Concon by Mr. Miers, who informs me that they will 

 probably form together a new genus, to which he proposes to give the name of 

 Micrcea. In both species the testa is entirely covered with moderately long 

 rigid hairs, which are directed upwards, and distinctly visible upon the dry 

 seed, longitudinally striated, appearing as if formed by the adherence of seve- 

 ral very slender tubes, and armed with numerous recurved hooks, which are 

 evidently hollow, and seem to communicate with the tubes ; each hair is usu- 

 ally terminated by two of these hooks, pointing in opposite directions. The 

 hairs do not discharge mucilage, or change their position materially on being 

 placed in water. 



A structure very similar to the above occurs in the seeds of Rhaphidospora 

 glabra, whose hairs differ chiefly in being shorter, thicker, and much more 

 closely beset with recurved teeth : as in Micra;a, they are entirely destitute of 

 mucilage, and may be clearly seen upon the dry seed, which they render per- 

 fectly hispid. 



Hairs, bearing some resemblance to those of Rhaphidospora, although much 

 reduced in size, occur on the seeds of a species of Dicliptera, brought by Afze- 

 lius from Sierra Leone, and contained in the Smithian herbarium. The testa 

 consists of small, nearly regular, hexagonal cells, and is thickly beset with 

 little rounded tubercles, of a paler colour, but formed of the same kind of 

 tissue as the rest of the testa. Each of these tubercles is produced into a very 

 short hair, terminated by from three to six recurved radiating hooks, and 

 having on the sides a few other hooks similar but smaller. In Dicliptera 

 Roxburghiana the hairs nearly resemble those of the preceding, but they do 

 not appear to be seated upon tubercles ; whilst in D. hupleuroides the seed is 

 covered with slightly prominent tubercles, formed of very minute hexagonal 

 cells, but destitute of hairs. 



