4i 6 Fry . — On Aggregations of Proteid in 
The cells of the growing-point and the pulvinus of young 
leaves are also full of proteid in a diffused form. 
Distribution in the leaves. The epidermis of the petiole and 
lamina of the leaves frequently contains crystalloids of the 
cubical form. 
In the mesophyll there is also a certain quantity of proteid, 
mostly diffuse or in irregular lumps. It is especially abun- 
dant in the cells of the palisade-parenchyma (/) lying over 
the small fibro-vascular bundles and tracheid-bundle-endings 
(Fig. 4). The ordinary elongated cells of the palisade-paren- 
chyma are here replaced by a number of small isodiametric 
cells with abundant cell-contents, consisting for the most part 
of irregularly formed masses of proteid. 
From the same figure it will be seen that the parenchy- 
matous sheath immediately surrounding the fibro-vascular 
bundles and tracheid-endings contains a number of spherical 
highly refracting bodies which at first sight seem to resemble 
the proteid masses of the stem ; their outlines, however, are 
more regular and they have a faint yellow tinge. Indeed 
they are not unlike oil-drops. They are not doubly refracting. 
They were insoluble in a mixture of absolute alcohol and 
ether, which showed they were not of an oily nature. They 
were also insoluble in 5 per cent, potash, and in saturated and 10 
per cent, common salt solution. Dilute nitric and strong hydro- 
chloric acid dissolved them completely. With dilute hydro- 
chloric they became granular, less highly refracting, and less 
spherical. 
When treated with ammonium chromate they gave no 
colour, showing the absence of tannin. Nor did they stain 
with corallin-soda, alkanet or methylene-blue. With eosin, 
Hoffmann’s blue and Hanstein’s reagent they stained deeply. 
With iodine they gave a deep yellow colour. 
Such a behaviour towards reagents would lead one to 
suppose that they might be of a proteid nature, but all 
attempts to confirm this by positive methods failed. With 
Millon’s reagent they gave a dull brown, with the xanthoproteic 
test I sometimes thought I obtained a faint yellow, but it was 
