UOW THK F'LANT I.IVES 123 



directly towards that slit, and t'Vim ihrouLrli it 

 to tlu» liriirlitt-r lii^lit. 



211. Plants aro smsiiivt' to gravitation, Tlio 

 llrst root of tli«> gerniinatin*^ s«>ed is so st'nsitivo 

 to gravity that it ordinarily p'ows downward, 

 whorevor it may Im^ and whatever may be its 

 position. On the other hand, the first shoot is 

 oppositely atYected by gravity, and if a potted 

 seedling is placed liorizontally thf stem soon 

 directs itself upwar<l. Whilf its g.'iicral tcnd- 

 t'ney is downward, the root is nevertheless 

 attracted in any direction by the presence of 

 water. 



'2\'2. The reactions of i)lants to their environ- 

 ments or surronndings may cause the plants to 

 vary, or to assume new I'nrms or characteristics; 

 and these new features may be of use to the 

 farmer. Thus, with more light, the better are 

 the roses or carnations grown un<ler glass; the 

 rii'ht-r the soil, the stronger is the gi-owth ; the 

 hi<rli«'r the altitude or latitude, the gi'eater is the 

 projmrtion of dwarf plants. 



SCGGESTIOSS oy rnAPTHIl mi 



182a. A salt \n the nuhtitanre formed from the nnton of an aoid 



with gome inorganio 8ul>Htiiiico or bane. The 8nlt mnr b» ncutml, 



- neither nrid nor alkaline. Thus sulfuric aoid niid lime fnnii 



the flnlt. iiulfnte of lini*' or ir\*psum : nitric aoid and oaiintio «odn 



form the aalt nitrate of soda; muriatic (hydrochloric) acid and 



