“0 
CONTRIBUTIONS TO BOTANY. 
lodged in the bud. The stamens are of very singular construc- 
tiouj and the figure in Aublet’s drawing affords a very ex- 
aggerated idea of their form. In all the preceding genera, I 
have described the bilobed anthers as being always distinctly 
4-ceIled before they burst, although after dehiscence, from the 
evolute mode of opening, they appear as if they had been only 
bilocular. In Poraqueiba, however, this 4-celled structure is 
rendered manifest in a much higher degree, for the cells are here 
perfectly distinct, and even separated from one another for a 
considerable distance by the intervention of a thick 4-sided 
pyramidal connective, composed of coarse reddish-coloured 
grains ; this is covered by a whitish adhering cuticle, consisting 
of a thicker crustaceous epidermis, and a thinner and more 
membranaceous inner tegument ; the narrow cylindrical pollen- 
cells, placed in the four salient angles of this connective, are 
formed by the continuation of the same cuticle, which here ceases 
to be adherent to the fleshy centre ; the epidermis forms the 
anterior or external casing of the crustaceous cells, while the 
inner tegument constitutes the posterior lining of the cavity, 
which is at the same time free from the connective, although in 
contiguity with it, and which seems to form the receptacle for 
the attachment and assimilation of the pollen-grains : the pollen- 
cells, therefore, in reality appear to consist merely of a linear 
separation between the two membranes at the angles of the 
anther, and in all transverse sections of the same placed under 
the microscope, no sutural break in the continuity of the epider- 
mis is discernible on either margin, where by its reduplication 
it becomes attached to the fleshy connective, nor is there any 
indication of a line of rupture or dehiscence. I confess therefore 
my inability to perceive, in any anther I have examined, the 
smallest appearance of bursting of the pollen-cells. M. Tulasne, 
on the contrary, states that they open longitudinally, by a fissure 
along the face of the connective ; but whether sinistrorsely, or 
dextrorsely, or alternately so, he does not explain. In the 
summit of the anther, the same continuous crustaceous cuticle 
is extended, and drkwn up into a short eylinder, or obtuse apical 
point, without any intervening connective, which apical point is 
again reflected downward along the upper portion of the anterior 
face of the anther, vanishing between the summits of the two 
anterior pollen-cells ; the nature or function of this process is 
not apparent. In the structure of its pistillum, Poraqueiba re- 
sembles that of Mappia. Of its fruit nothing is recorded, more 
than that in its unripe state it is spherical, smooth, and mucro- 
nated. Although M. Tulasne has given a very elaborate descrip- 
tion of this genus, it appears to me the following is a more 
correct expression of its character. 
