LIME AND MAGNESIA IN PLANTS. 



37 



Very great differences are revealed also in the comparison of the 

 wood with the seeds in this regard, the lime content being relatively 

 increased in the wood: 



Abies pectinata, seeds 1 part magnesia to 0.09 part lime. 



wood L part magnesia to 4.62 parts lime. 



Phut.* sylvestris, seeds 1 part magnesia to 0. 12 part lime. 



wood . 1 part magnesia to 1.60 parts lime. 



During the fruiting year of a beech tree 150 years old. II. Weber ffl 

 several years ago made some interesting observations on the migration 

 of magnesia. He found that magnesia as well as nitrogen migrated from 

 the trunk to the points of seed formation, and in a smaller measure 

 also sulphuric and phosphoric acids did the same. The decrease of 

 the magnesia in the wood extended to ninety annual rings. The wood 

 of the tree was analyzed in zones of thirt}^ rings each. The percent- 

 age of lime and magnesia in the ash are given as follows, as is also for 

 comparison the composition of a beech tree of the same age which 

 had grown near by, but which bore no fruits that year: 



Lime dud magnesia in a fruiting beech mid in <i emit ml beech. 



As shown by the table, there was relatively a most striking decrease 

 of magnesia to lime in zones 1, 2, and 3 of the trunk of the seed beech 

 as compared with the corresponding zones from the control beech. 



The leaves of aquatic plants are also rich in lime. The proportions 

 of magnesia and lime were found to be, in Xympltnut lutea, 1:8.5; in 

 Lemna, 1:3.3 to 1:7.6; and in Elodea canadensis, 1:8 .4. Also algoB 

 show similar proportions, as seen from the ash analyses of Spirogyra 

 niiida by Pennington (1896) and of fucoids by Godechens (1854). 

 Algre incrustated with calcium carbonate must, of course, be here 

 excluded. 



From what has been said under this head it will be seen that the 

 analytical investigations of the ash of plants show (1) that lime and 

 magnesia are present in every part of the plant, and (2) that the leaves 

 contain relatively more lime and the seeds relatively more magnesia 

 than the other parts of the plants. These characteristics can not be 

 accidental, but must be the result of certain functions. 



" Forstlich. Naturw. Zeitschr., 1892. 



