Notes. 
383 
In the Mackay herbarium Spergula was not represented, nor were 
Irish specimens contained either in the herbarium of Mr. A. G. More, 
or in the British collection at Trinity College, Dublin; but in the 
general collection in the latter herbarium was a specimen with darker 
wings to the seed, which I should, with some doubt, refer to S. 
pentandra , and which was simply labelled ‘ S. pentandra , Dublin/ 
without date or collector's name, and in a writing not familiar to 
Professor Wright, who kindly showed me the specimens referred to. 
G. CLARIDGE DRUCE, Oxford. 
ON THE CHANGES IN THE ENDOSPERM OF RICXNUS 
COMMUNIS DURING GERMINATION 1 . — The seeds of Ricinus 
communis , the castor-oil plant, consist of a central embryo which has 
two large foliaceous cotyledons embedded closely in a mass of en- 
dosperm to which, pending germination, they closely adhere. The 
cells of the endosperm which are in immediate contact with the 
cotyledons are empty and their walls pressed closely together, 
forming a layer which, though occupying but little space, really consists 
of several ranks of cells. Beyond this layer the mass of endosperm- 
cells lies, and each cell contains a matrix or network of protoplasm 
saturated with the oil. This does not exist in the condition of 
globules or drops, though it can be extracted by pressing the tissue. 
In the interspaces of the protoplasmic network the proteid reserve 
materials are found. They are the well-known aleurone-grains, 
each consisting of an ovoid mass of proteid matter in which are 
contained a crystalloid, also proteid, and a globoid composed of 
a double phosphate of calcium and magnesium. The cell-walls are 
thin, so that there is but little cellulose present. Of other carbohydrates 
there is a trace of sugar, but no starch. No glucoside exists in the 
cells. 
Under favourable conditions germination is completed in five to 
seven days. At its onset the mass of the endosperm begins to swell, 
and speedily the radicle emerges from the testa; soon the testa 
ruptures, and the endosperm, still increasing in bulk, is pressed 
outwards, the testa falling off at the apex of the seed. The endosperm 
then forms a white caky covering to the cotyledons, which adhere to 
it less and less completely. The mass of endosperm, now much 
1 Read before the Royal Society, Jan. 30, 1890. 
