the two vesicles is filled with a dense mucilaginous sap, of the same 
quality as that which occurs in the cellular texture of the plants in 
which they are found. When placed in water, which is of considera- 
bly less specific gravity than the sap, the ordinary effects of Endos- 
mose takes place. The water penetrates the coat of the outer vesicle, 
fills and distends the space between the two, until pressing strongly 
upon the inner vesicle, it forces a discharge of its contents. The 
biforines are not confined to the parenchyma of the leaf, but occur in 
other parts of the cellular tissue, and are even found intermixed with 
_ the pollen after it is discharged from the anthers. Our figure 5, repre- 
sents part of a mass of pollen collected on the surface of the spathe, 
after it had fallen from the anthers. It formed so pleasing an object 
for the microscope, that we thought a particular description of it 
might be acceptable. 
Ist. Spherical pollen grains, as at (a), of different sizes; their con- 
tained granules appearing as a dark central mass surrounded by a 
transparent coat. 
2nd. Pollen grains, as at (6), of irregular shapes; resulting from 
modifications of the spherical form, by the peculiar action which pro- 
duces the pollenic-tubes. In some cases the grain was oblong; in 
others there were one, two, or more prominences upon the surface; 
and in others the tubes were more or less completely developed, with 
the granules either still contained in them or dispersed. 
3rd. The Biforines, at (¢ c). In some cases the cell was more or 
less irregular. They occur either singly, or lying two or three 
together. 
4th. Crystals, from minute specks up to the size of the grains of 
pollen. Some appeared like squares, as at (d), with dark angles; or 
with diagonal lines; others, like oblongs with a dark triangle on each 
end, as at (e). These appearances clearly indicate their form to be a 
square prism capped at each end with a tetrahedral pyramid; and in 
all probability they are composed of oxalate of lime, 
5th. Raphides, or slender spicule, at (f), similar in appearance 
to, but larger than, those contained in the “biforines.” 
The Dumb Cane is further remarkable from the extremely acrid 
properties of its juice, the smallest portion of which when applied to 
the mouth is sufficient to cause acute pain. It has obtained its 
popular name from its swelling the tongue and mouth of any one who 
