164 Rendle. — On the development of 
ference in solubility is noticed, the grains now reacting like 
those of ripe seeds, dissolving completely in 10 per cent, and 
saturated solutions of common salt and potassium phosphate, 
and also in 1 per cent, of hydrochloric acid, though still insoluble 
in water. One gets sometimes preparations in an intermediate 
state with the grains only partly soluble, even after twenty 
hours’ exposure to the reagent. It has been shown 1 that the 
aleurone-grains of ripe seeds contain several distinct proteids 
belonging to the albumose and globulin groups, and the 
change in solubility during development may be the ex- 
pression of the breaking down of some complex proteid 
substance, originally secreted by the protoplasm, into the 
several simpler proteids known to occur in the ripe seed, 
and it is during this process that one would expect the 
separation of solid mineral constituents to take place in 
cases where they are found in the ripe seed. The grains 
continue to increase in size but are at first rather watery, 
and in absolute alcohol material show a vacuolation, probably 
due to the reagent, the denser part forming an external ring, 
or very often collecting chiefly on one side and forming a 
crescent (Fig. 4); the ring or crescent stains well with the 
above-mentioned dyes, while the portion inside remains clear. 
On solution, however, the denser portion is seen gradually to 
diffuse throughout the whole, forming a homogeneous struc- 
ture (Fig. 5) ; when this stage is reached the seed is beginning 
to get ripe, as indicated by the end of the radicle turning 
yellow. As ripening goes on the denser part encroaches 
more and more on the clearer, and by the time the yellow 
coloration has extended up the radicle and is affecting the 
cotyledons, the majority of the grains have again come to 
stain homogeneously, as in the ripe seed, indicating increase 
in quantity of the denser part and loss of water of the grain 
coincident with the general drying of the seed. The proto- 
plasm has meanwhile been diminishing, and the starch-grains 
have by the end of this process disappeared, drops of oil 
1 Vines, Journal of Physiology, III, 1881. 
