58 THE Mrcroscors. 
: To ENS Sean: 
7 ¥ ha a 4 > " 
the microscopical structure of the Dalmatian flower. In the florets 
of the ray the limb consists of an upper and a lower epidermal layer; 
the former of these having the cells developed into papille, which 
_in the dry state become laterally contracted and readily break away 
from the base of the cells, and are easily found in the powder; the 
_ opposite sides of these papille enclose an angle ranging between 
~. 55° or 60°, and 90°; the walls are fairly striated the lower 
epidermal cells being elongated with sinuous walls. The nerves are 
nN 
Ae 2 
1. Pollen grains and epidermal papille of Dalmatian insect flower. 
2. Pollen grains and epidermal papillee of Persian insect flower. 
composed of narrow spiral trachz. The florets of the disk consist of 
elongated parenchyma, most of the cells containing a solitary small 
klinorhombic crystal of calcium oxalate, or less frequently, a small 
stellate cluster of crystals. The cellsin the papille of the stigma are 
longer than broad, and almost cylindrical. The polen grains which 
are abundant in the powder, are globular, furnished with spines, and 
have a diameter from 30 to 40u. Sclerotic, elongated, pitted cells, 
and narrow spiral vessels, form the tissue of the involucral scales, 
the cells becoming membranous at the margins. The disc consists of 
irregular parenchyma and fibro-vascular bundles containing many 
spiral vessels. _In the peduncle the parenchyma is made 
up of large cells, with walls bearing few large pits, which are 
yery sparsely distributed. The Persian Insect powder, which may 
be substituted for or used to sophisticate the Dalmatian powder, pre- 
sents almost identical histological characteristics. The papille in 
the former are heavier, larger, and somewhat thicker at the apex, 
the sides making an angle of from 20° to 50°. 
A metuop of distinguishing between quartz and feldspa in rock 
sections has been suggested by Becke in the Mineralogische und 
Petrographischi Mitthentingen, X. The former mineral is dissolved 
by hydrofluric acid, while the feldspa so treated yields an amorphous 
aluminium fluosilicate, which is capable of staining with an aniline 
color. 
