52 
THE AMERICAN BOTANIST. 
is apparent. The tongue, roof of the mouth and lining of 
the throat seem pierced hy a thousand tiny needles. A 
careful chemical and histological examination of fresh 
taro plants was made for me by Mr. Lyman F. Kebler 
and Mr. B. J. Howard. The result of their examination 
and experiments tend to corroborate the theory that the 
burning sensation experienced on chewing the leaves is 
not caused by an acrid fluid but by minute needle-like 
crystals of calcium oxalate contained in the tissue. Many 
plants in which these cr\'Stals are found are not acrid to 
the taste but most of the Arace^, including our own 
Indian turnip or Jack-in-the-pulpit, are intensely so. In 
some plants the crystals are developed singly in a cell of 
the parenchyma; in other cases they are in the form of 
radiating clusters, while in others, including several fami- 
lies of the monocotyledons, they form compact bundles 
called raphides. These raphides are sometimes found in a 
cell which can easily be separated from the remaining 
tissue of the plant. In Caladium and Alocasia they are 
inclosed in what appears to be elongated transparent 
capsules filled With mucilage. These capsules or cart- 
ridges are situated in the partition w^ails between two 
vacuoles, their ends projecting into the adjacent vacuoles. 
When the vacuoles become filled with water by being 
crushed in chewing, or when artificially macerated, the 
mucilage absorbs water through the capsule walls in- 
creasing the volume so that it exerts such a pressure that 
the needles are ejected with considerable force from the 
capsule at one or both ends where the cell wall is thinner 
than at the sides.— From Useful Plants of the Island ot 
Guam by W. E. Safford. 
pRmTiNG OF A Palm.— It is the habit of several species 
of palm to fruit but once in a lifetime, the trees dying soon 
after the fruit is ripened. According to Gardening World 
two photographs of palms of this kind— Corypha elata— 
were recently sent to the Linnaian Society. One of the 
» shown had produced 
ighing half a ton in the 
in the aggregate ! 
than fiftj' thousand 
