152 



PLANT STUlilKS 



:ui Hc.tivc siciii ))(! cut and jihuigeil into water stained with 

 an aniline color called eosin,* the ascending water will stain 

 its patliway. Al'Ler some I inie sections throngli the stem 

 "will show Ihat tjie water has t|-a\-eled upwards through it, 

 and tlie stain will point out the regioii of the stem used in 

 the mo\ement. 



Jn general, iliere.rore, tlie cai'lion dioxide is ahs(irhed 

 directly frdui the air hy the lea."\'es, and the water is ab- 

 sorhed hy the root from the suil, a]id moves n}iwai'ds tlirough 

 the stem iido (he leaves. An interesting fact ahout these 

 raw materials is that thev are very common waste products. 

 They are waste; products hecause in most life-pi'ocesses tliey 

 cannot l)e taken to jiieces and used. 1'lie fact that they 



can he used in })hotosyntliesis 

 shows that it is a very re- 

 markaJjle life pro(/ess. 

 1*^© lh= ('-) ('Jildroplus/s. — Having 



olitaiiH.Ml some knowledge of 

 the raw materials used in 

 w. 11- V 1 n ,1 r photosynthesis, and their 



Uii- \L-.iiti! j''iitoiNa,ii\inK]ii'^cii]nrn- sourci'S, it is necessai'y (o 

 '''""'■"■ consider the iilani, nuichinery 



arranged for the woi'k. lu the workiug leaf cells it is 

 discovered that the c(jlor is due to (he preseu(/e of vei'y 

 small green bodies, known as chhu'ojibvll li(]dies or rliloro- 

 j/lu^h (see i''ig. 1-15). 'hliese consist of the living substance, 

 known as l)rotdj)lasm, a,iid the gi'eeu sta.iu called cldoro- 

 [ihyll ; therefore, each cbloroplast isali\iug body (pldstid) 

 slaJucd green, it. is iu these cliloi-o[ilasts that the W(U'k of 

 pholosyuthesis is (huie. in oi'der that they may work it 

 is necessary foi' tiiem lo obtain a sup]il\- (d' euerijy froiu 

 some outside source, and the soui'ia; used iu ua.ture is sun- 

 light. The green sta.iu (cliloropliyll) seems to be used in 

 absorbing the necessary energy fi-om sunlight, a.ml (he 



Tin; eiillUlleliL'l- j^'rudljS el' J-ed ink -.Wr USII.'lll)- ,s(illUiells et' resin. 



