CALCIUM OXALATE IN SEEDLINGS OF ALSIKE. 401 
Plants grown with a reduced water-supply I found to be always 
much longer in forming crystals than those to which plenty of 
water was given. 
A number of plants were also grown in nutrient solution 
without calcium. During the time the experiment was carried 
on, namely 39 days, the plants grew as well as specimens supplied 
with a complete Knop’s solution, but no crystals appeared in any 
part of the plants. 
A number of petioles of the leaves I subjected to gradually 
increasing strain up to 75 grams during 14 or15 days. Bya 
comparison of leaves of practically the same age on the same 
plant, I found that the number of crystals formed at first in the 
petiole decreased very largely under strain. 
The crystals in Alsike and the majority of leguminous plants 
I have examined are either in the form of short prisms or tetra- 
gonal pyramids, and invariably occur in the first row of paren- 
chymatous cells next the fibres on the bast side of the vascular 
bundles. They are never quite in the middle of the cell-cavity 
in which they are produced, but lie close to the side immediately 
adjoining the fibres, and each crystal is imbedded in, or attached to, 
a matrix of a mucilaginous or pectic substance which is adherent 
to the inside of the cell-wall (figs. 3 & 4, p. 399). The crystal 
matrix stains readily when treated with methylene-blue in caustic 
soda, the surrounding cell-walls remaining colourless under the 
same treatment (fig. 6). 
The position of the crystals is indicated in the portion of the 
transverse section of a petiole given in fig. 2. In the leaves of 
the plants the crystals occupy a similar position in regard to 
fibres as in the petiole, but are met with opposite both the wood 
and bast next the upper and lower surfaces of the leaves (fig. 5). 
The object of my present communication is mainly to describe 
the distribution and first appearance of calcium-oxalate crystals 
in seedlings grown under various conditions; and it would be 
premature to make positive assertions in regard to the processes 
involved in their formation. The whole evidence, however, 
obtained during the study of these plants seems to point to the 
conclusion that the production of the crystals is connected with 
the formation of fibres in the petioles and leaves. Wherever 
there is an abundant development of fibres, as near the ends of 
the vascular bundles in the leaves, and in the simple stipular 
bundles, these crystals are especially numerous. In the upper 
LINN. JOURN.—BOTANY, VOL. XXXV. 24 
