On the Fruits and Seeds of Rhamnus. 2 3 
partly because it had air clinging to its dry cells. In ten 
minutes the floating raphe was thickly covered with the 
golden yellow precipitate of rhamnetin. In twenty minutes 
the clouds of precipitate were falling in the tube : in less than 
an hour there was a precipitate at the bottom of the test- 
tube, which measured mm. in depth, and which was many 
times larger than the raphe. 
Examination of the raphe shows that it consists of a slender 
vascular bundle running up the groove in the seed, which is 
dorsal, and cellular prolongations like wings from its sides : 
these two wing-like expansions of thin- walled parenchymatous 
cells line closely the sides of the groove (Fig. 21). In fact we 
may regard the vascular bundle of the raphe as the line round 
which the folding occurs which gives the seed its grooved 
appearance, and therefore its horseshoe-shaped transverse 
section. When the folding of the seed occurs, it doubles back 
with it the two wings of the raphe, and the margins of these 
wings end in the thickened ridges of the testa, as shown in 
the figures. 
I also examined the contents of the cells of the raphe. 
When a thin section of the dry raphe is placed in strong 
glycerine the cells are seen to contain a brilliant, oily-looking, 
colourless substance which does not fill up the cavity but is 
driven aside by large vacuole-like chambers in which a few 
brilliant granules may be observed. If placed in very dilute 
solutions of caustic potash, the cells and their contents at once 
swell up, and the oily-looking matrix dissolves almost entirely, 
but not quite ; drops of clear oil-like substance flow together, 
and escape. 
When placed directly in water, the colourless oil-like matrix 
froths up in a most remarkable manner, and oily-looking 
drops escape ; these drops are vacuolated, however, and 
something seems to be dissolved from them also. In one per 
cent. Osmic acid solution, the vacuolated oily masses slowly 
turn brown. Absolute alcohol dissolves a large proportion of 
their substance, but not all. 
I have examined the fruits and seeds of four other species 
