i68 BOTANY AND PHARMACOGNOSY. 



grapes. It also occurs in combination with other principles, form- 

 ing the glucosides. 



Levulose (fructose, fruit-sugar or levo-glucose) is associated 

 with dextrose, occurring in some instances even in larger quan- 

 tities than the latter. 



Sucrose (saccharose or cane-sugar) is found rather widely- 

 distributed, as in the stems of corn, sorghum and the sugar-cane ; 

 in roots, "as the sugar-beet ; in the sap of certain trees, as sugar- 

 maple and some of the palms ; in the nectaries and sap of certain 

 flowers as fuchsia, caryophyllus and some of the Cactace^; in 

 seeds, as almond and chestnut, and in various fruits, as figs, mel- 

 ons, apples, cherries. In some plants, as in sugar-cane, the yield is 

 as high as 20 per cent. It crystallizes in monoclinic prisms or pyra- 

 mids and forms insoluble compounds with calcium and strontium. 



Maltose is found in the germinating grains of cereals (see 

 malt) ; it forms colorless, needle-shaped crystals resembling those 

 of dextrose, and forms compounds with calcium, strontium, 

 barium and acetic acid. 



Trehalose occurs in some fungi, as ergot and Agaricus mus- 

 carius — the latter containing as much as 10 per cent, in the dried 

 plant. 



Mannitol occurs in the form of needles or prisms and is found 

 in the manna of Fraxinus ornus to the extent of 90 per cent. It 

 is. also found in some of the Umbelliferse, as Apium graveolens, 

 some of the Fungi and seaweeds, and is rather widely distributed. 



Dulcitol, which is closely related to mannitol, is found in 

 Euonymus europaus and in most of the plants of the Scroph- 

 ulariaceae. 



Gentianose occurs in the root of Gentiana lutea. 



The alkaloids probably arise in the protoplasm. Later 

 they appear in the cell-sap in combination with various plant 

 acids, as malic, tannic and others, and may be precipitated by 

 the so-called alkaloidal reagents. They occur in greatest amount 

 in those cells which are in a potential, rather than an active con- 

 dition, being associated with starch, fixed oils, aleurone grains, 

 and other reserve products, in the roots, rhizomes and seeds. 

 They are found in fruits in greatest amount during the develop- 

 ment of the seed, but after the maturing of the latter they slowly 



