Periodical Literature. 519 



these may occur also on sandstones, etc. ; the preference becomes 

 first visible when competition of plants enters into the problem. If 

 Rhododendron hirsuttim and ferrngineum occur in a region to- 

 gether, the first is found only on lime, the second on lime-poor 

 soils ; if, however, only one of them is endemic, it occurs on either 

 soil. 



There must be recognized the indirect effect of lime on the soil, 

 and the direct effect on the life processes of the plant. Carbonate 

 of lime has most significant influence on physical and chemical 

 conditions of soil and its presence expresses itself in the vegeta- 

 tion directly. The detail of this influence of carbonate of lime 

 is discussed : it counteracts acidity ; it influences solubility of 

 other important minerals; it promotes granular structure and 

 thereby moisture conditions favorably ; it promotes greatly activity 

 of bacteria and prevents formation of dry turf and promotes 

 favorable humification. Every lime soil is, however, not rich in 

 carbonate of lime, and hence does not exhibit these advantages. 



As regards the direct influence of lime on plants, there is still 

 more hypothesis than demonstrated fact to be had, some investiga- 

 tors trying to establish such a direct relation, others considering 

 the influence entirely indirect. Grabner's hypothesis divides plants 

 into entrophic and oligotrophic, i. e. those making large require- 

 ments on minerals and those having a small requirement, and as- 

 serts that lime soils abound also in other minerals, hence entrophic 

 plants are found on lime soils. But the assertion of the presence 

 of large quantities of minerals in lime soils does not always coin- 

 cide with facts. 



All plants need lime for their development, although according 

 to Hausteen much less than other minerals. Indeed, some fungi 

 and algae can dispense entirely with it. Even calcofuge plants 

 like Pinus pinaster and Castanca vesca absorb considerable quanti- 

 ties of lime. Only these calcofuge plants are more easily injured 

 by excess of lime. Kerner's experiments are convincing in this 

 resptct. The investigations of the behavior of sphagnum species, 

 which are considered most calcofuge, by several authorities are 

 contradictory, but it would appear that the degree of acidity stands 

 in relation to the sensitiveness to lime reaction. Apparently the 

 presence of potash also has an influence upon the effect of lime. 

 Engler is cited with the statement that calcofuge Castanea thrives 



