80 BOTANY r.urr i 



Carbohydrates are transported in a plant principally in the form 

 of glucose ; cane sugar, on the contrary, is stored up as a reserve 

 material, as for example, in the sugar-beet, in the stems of sugar- 

 cane, and in other plants from which the sugar of economic use is 

 derived. 



INULIN', a carbohydrate in solution in cell sap, behaves in the same way in the 

 ( ''ompositae. Treated with alcohol, inulin is precipitated in the form of small granules, 

 which may be redissolved in hot water. When portions of plants containing much 

 inulin, such as the root tubers of Dahlia variabilis, are placed in alcohol or dilute 

 glycerine, the inulin crystallises out and forms sphserites, spheroidal bodies com- 

 posed of radiating crystal needles arranged in concentric layers. Amides such as 

 GLUTAMIN and ASPARAGIN are also generally present in the cell sap. There are 

 frequently found dissolved in the cell sap TANNINS, ALKALOIDS, and GLUCOSIDES. 

 such as coniferin, hesperidin, amygdalin, solanin, tvsculin, saponin, and also bitter 

 principles related to the glucosides. Organic acids (malic, formic, acetic, and 

 oxalic acids) are also of frequent occurrence in the cell sap ; thus, malic acid is 

 usually present in the leaves of the succulents. For the most part, these organic 

 acids unite with bases, and the salts which are formed often crystallise. Of acid 

 salts, which are less frequent than free acids, the binoxalate of potassium found in 

 Field Sorrel (Rumex) and Wood Sorrel (Oxalis) deserves special mention. Species 

 of Salicornia and Salsola contain sodium oxalate. The cell sap always contains 

 dissolved inorganic salts, especially nitrates, sulphates, and phosphates. The 

 different vacuoles of the same protoplast may have distinct contents ; thus one 

 may contain tannin and another be free from it, or one may have coloured and 

 another colourless sap. 



The cell sap is often coloured, principally by the so-called ANTHO- 

 CYANIN, which Hans Molisch, at least in some cases, regards as being 

 a non-nitrogenous glucoside ( 81 ). This is blue in an alkaline, and red 

 in an acid reacting cell sap, and, under certain conditions, also dark 

 red, violet, dark blue, and even blackish-blue. Anthocyanin can be ob- 

 tained from the super-saturated cell sap of a number of deeply coloured 

 parts of plants in a crystalline or amorphous form. Blood-coloured 

 leaves, such as those of the Copper Beech, owe their characteristic 

 appearance to the united presence of green chlorophyll and antho- 

 cyanin. The different colours of flowers are due to the varying 

 colour of the cell sap, to the different distribution of the cells 

 containing the coloured cell sap, and also to the different com- 

 binations of dissolved colouring matter with the yellow, orange, 

 or red chromoplasts and the green chloroplasts. There is occa- 

 sionally found in the cell sap a yellow colouring mattter known 

 as xanthein ; it is nearly related to xanthophyll, but soluble in 

 water. 



2. ONTOGENY OF THE CELL 



The Origin of the Living Elements of Protoplasm. All the 



nuclei in an organism owe their origin to the nuclei of previous 



