80 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
species, of cells with thick walls, the thickening being produced by a 
substance which is laid down as a secondary structure during the ripen- 
ing of the seed, and which is used up during the period of germination 
as nutriment for the young plant. 
Reserve-cellulose appears as such, on the walls of the cells, soon 
after the endosperm is formed. Sugar and oil are present in the cells 
before the appearance of reserve-cellulose, and during the process of 
wall-thickening ; of these sugar is first detected. The reserve-cellulose 
appears first at the angles of the cells, and thence extends to the walls. 
The cells of the endosperm, near the chalaza, are the first to have their 
walls thickened ; those next the integuments are next affected ; and the 
cells near the embryo are the last to mature. In some seeds (Iris) 
reserve-cellulose in its younger stages has the property of swelling with 
water and going over into a mucilaginous modification. This swelling 
is noticeable in the mature seed after long-continued boiling in water. 
The reserve-cellulose of Paris and Trillium- seeds swells with water before 
maturity. This is true of Paris , when the seed is ripe, and will un- 
doubtedly prove true of Trillium also. With the exception of Paris and 
Trillium , the association of starch with reserve-cellulose has not been 
observed as a reserve constituent of the cells in seeds of Liliaceze. In 
Colchicum starch is found outside the endosperm in the crest of the 
ripening seed. In Galantlius, Scilla, Lloydia, and Narcissus it is found 
in the endosperm-cells during the latter stages of the ripening of the 
seed, and is perhaps a sign of arrest in processes of development. When 
the seed is fully matured starch is not present. In Convallaria, Fritil- 
laria, Tojieldia, Anthericum, and Asphodelus , it is never present in the 
seed. In Asparagus and Polygonatum starch-builders, with minute 
grains of starch, are found in certain cells of the endosperm before the 
thickening of the wall begins ; during the processes of thickening they 
are not visible. In Iris a little starch appears in the cells of the chalaza, 
never in the endosperm, before any thickening takes place. 
Crystalloids in the Flowers of Leguminosae.* — Dr. P. Baccarini 
finds crystalloids present in the floral organs of a considerable number 
of Leguminosa?, mostly belonging to the Genistese and the Phaseolere. 
Negative results were obtained with other species. They were found 
especially in the petals of fugacious flowers, and cannot therefore be 
regarded in the light of reserve food-material, like the crystalloids of 
seeds or tubers. 
Starch-Grains. | — Dr. A. Meyer gives a detailed account of the present 
state of our knowledge of the mode of formation and structure of starch- 
grains, together with the results of an extensive series of observations 
of his own (chiefly on Adoxa, Hordeum, Oxalis, Pellionia, Hyacinthus , 
and Cyrtodeira). He regards starch-grains as true spliserocrystals, in 
every way analogous to the sphserocrystals of inulin ; and as composed 
of two substances, one of which, a-amylose, can be obtained separately 
in the crystalline form, while the other, /3-amylose, cannot be isolated in 
crystals. Acicular crystals, or trichites , of amylose occur in the starch- 
grains, arranged more 'or less radially, and more crowded in the denser 
* Bull. Soc. Biol. Ital., 1895, pp. 139-44. 
f ‘ Unters. iiber d. Starkekorner,’ Jena, 1895, 9 pis. and 99 figs. See Nature, lii. 
(1895) p. 640. 
