Mr Parkin , On a reserve carbohydrate , 
139 
On a reserve carbohydrate , which produces mannose , from the 
bulb of Lilium. By J. Parkin, M.A., Trinity College. 
4 March 1901.] 
Besides starch the bulbs of members of the genus Lilium 
contain another reserve carbohydrate. It exists as a sort of 
mucilage in the cell-sap of all the parenchymatous cells of the 
bulb-scales. Alcohol precipitates and hardens it, so that sections 
of scales preserved in spirit show each cell filled with a solid block 
of mucilage, in which the starch grains are embedded. On treat- 
ment with water the mucilage swells and gradually dissolves, 
liberating the starch grains. Thus the alcoholic material presents 
somewhat the same microscopic appearance as that of other 
monocotyledonous reserve organs containing starch and inulin, for 
example the Hyacinth bulb described in a former paper 1 . Lilium, 
however, did not respond to the microchemical tests used there, 
and so these bulbs were merely referred to as possessing starch 
and not inulin. 
In some recent papers by Leclerc du Sablon 2 on reserves of 
bulbs and tubers, he speaks of the carbohydrate soluble in water 
but insoluble in strong alcohol as dextrin. No conclusive evidence 
is given to prove that it is such. He seems merely to have found 
that it is readily hydrolysed by an acid to produce sugar reducing 
Fehling’s solution. The monocotyledons he mentions more par- 
ticularly as possessing dextrin in their reserve organs are Lilium 
candidum, Hyacinthus orientalis, Tulipa Gesneriana and Ophrys 
aranifera. 
Proof has previously been given 3 that his supposed dextrin in 
the Hyacinth bulb is inulin, or at any rate a carbohydrate 
producing fructose (levulose) on hydrolysis. 
The carbohydrate occurring along with starch in the bulb of 
Lilium candidum has now been chemically examined, and found 
to be one yielding mannose and not glucose on hydrolysis. 
Chemical examination. The bulbs used were taken from the 
ground on September 20th, at a time when the foliage was 
withering. The scales were removed, cleaned, sliced in pieces and 
allowed to dry at the ordinary temperature in a current of air 
They were then ground up. 
About 17 grams of this dried material were taken and 
1 Parkin, Phil. Trans. Roy. Soc. Lond., ser. B, vol. cxci. (1899), pp. 61 — 64. 
2 Leclerc du Sablon, Rev. Gen. de Bot., 1898. 
3 Parkin, Annals of Botany, vol. xiv. 1900, pp. 155 — 157. 
