178 



BOTANICAL COLLECTIONS, 



INCLUDING VEGETABLE PHYSIOLOGY. 



Experiments on the Germination of Seeds. — Professor Vogel, of Munich, 

 has made a series of experiments on the germination of seeds in various 

 organic substances. The seeds employed were wheat and barley. They 

 were sown in the substance to be tried, and moistened daily with distilled 

 water. From the results of the experiments, the author arranges these 

 substances into three classes, according to their effects on germination. 



1. Those in which seeds did not germinate in the slightest degree. They 

 are carbonate of barytes, hydrates of lime and barytes, powder of iodine, 

 kermes, golden sulphur of antimony, magistery of bismuth, arseniate of lead, 

 carbonate of copper, green oxide of chrome. No germination took place 

 when the seeds were moistened with dilute solutions of sulphate of copper, 

 arsenious acid, corrosive sublimate, nitrates of mercury and silver, and 

 muriate of barytes. 



2. The substances in which the seeds germinated feebly, were, carbonate 

 of magnesia, copper filings, crude antimony, calomel, red oxide of mercury, 

 watery solution of iodine. To this class also belong, in reference to wheat, 

 sulphate of barytes, and oxide of zinc ; in which substances, however, barley 

 springs very readily, and grows vigorously. 



3r The third class comprehends those substances in which the seeds 

 germinated with vigour, and the young plants throve well. These were, 

 white marble, carbonate of strontian, peroxide of tin, litharge, red oxide, 

 and phosphate of lead, black oxide of manganese, and cinnabar. In refer- 

 ence to barley, sulphate of barytes, and oxide of zinc belong to this class ; 

 in which substances wheat germinates but feebly. 



The author had expected to find, that substances which exerted a noxious 

 influence on the animal economy, would prove equally inimical to vegetation; 

 but the results, as he candidly admits, exhibit several instances which cannot 

 be reconciled with this view Isis, 1830, p. 499. 



Course of the Sap Professor Hayne, of Berlin, gives the following novel 



views respecting the course of the sap in vegetables : — 



The sap moves in the direction in which plants grow and increase, whether 

 in length or breadth ; that is, downwards in the root, and upwards in the 

 trunk and branches. It is absorbed from the soil by the bark of the root, 

 and rises in the intercellular spaces of the parenchyma, till it reaches the 

 junction of the root and trunk, which point the author calls the nodtis indif- 

 ferentialis. Arrived there, it enters the vessels, and becomes the nutritious 

 juice or chymus ; it then proceeds along the vessels to their extremities, 

 descending in the root, and mounting upwards in the trunk, in which passage 

 i^ is continually transmitting a portion through the walls of the vessels into 

 the intercellular canals or passages of the longitudinal cellular texture, 

 which portion having undergone a change in its properties, becomes the 

 formative juice or enchymus, appearing as a thickish transparent fluid, in 

 which deposits take place in the form of fine filaments and granules. Out 

 of the filaments, the spiral or annular vessels are probably formed, as Kieser 

 supposes, and cells are formed from the granules. The sap which remains 

 after these new formations, in the root of dicotyledonous plants, most 

 probably enters the intercellular canals of the pith ; but, in the stem, it is 

 conveyed into the intercellular canals of the leaves, where it undergoes 

 farther changes in composition. In the root, stem, and branches of dico- 

 tyledonous plants, this juice is very probably also conveyed along inter- 

 cellular canals, from the centre to the circumference, where it contributes to 



