. 
EEA 
ERT ed 
1880.] Microscopic Crystals contained in Plants. 777 
toooth of an inch in diameter. When a collection of these is 
met with they form a beautiful field, which I think is only sur- 
passed in beauty by the sphzraphid tissue in the testa of the elm. 
These crystals would not answer to any of the chemical tests 
except those for calcium, so that I have reason to believe that the 
base was combined with some organic acid, perhaps tartaric. 
Vitis estivalis and V. cordifolia abounded in both sorts of crys- 
tals, but neither were as large as in the common grape. In Am- 
pelopsis quinquefolia I found raphides, but they were often free, 
that is they were not in a close bundle. The sphzraphid tissue 
is very fine in this species. Each crystal seems to form a nucleus 
to a single cell. Thecells are placed very regularly and sym- 
metrical in form. The blackberries contained raphides in more 
abundance and of a larger form than those of the grape fruits, 
but the largest were in the leaves and petioles of the younger 
shoots. The sphzraphides were not as large as those of the 
grape. As in the genus Vitis the crystals of this species, except 
those mentioned last, seemed to contain lime as a base and phos- 
phoric acid. 
In this family all the crystals contained in the fruit, except the 
raphides, gave the tests for lime, but failed to give the tests for 
the common acids, so that I think it probable that the base was in 
combination with some organic acid. I expected to find in this 
family more acicular crystals, but in this I was disappointed. 
The next order that I shall report upon, as is well known, is 
the largest natural order, and is represented by a number of — 
hundred species, it being universal. This family, the Composite, — 
is well represented in the Northern States. Raphides are not as 
common in this family as in the other two, Araceae and Vitacee, 
but forms of all three classes do occur. I have only found the 
needle-shaped crystals in the ovary or fruit, and sometimes in the 
receptacle and involucre. In some species minute cubical crystals 
occur which dissolve with effervescence in acetic acid. Globular 
masses of crystals known as inuline are quite common. I did 
not find the raphides in bundles except in one case, Achillea mil- f 
lifolium, which contained in the receptacle, on the average, about 
twenty raphides in each bundle; in all other cases when raphides 
were found- they were single, which was perhaps due to some 
disturbance. 
In /nula helenium I could find no crystals except the globular 
VOL. XIX.=NỌ. XI, 50 
