MICRO-PHYSICS OF THE CELL. 43 



lines C and D, at the beginning of the orange, another 

 faint narrow band (band IV.) in the green a little to 

 the left of the line E t a broad faint band (band V.) in 

 the blue to the right of the line F, a still broader 

 faint band (band VI.) in the blue and indigo just to 

 the left of the line G-, and finally a broad faint band 

 (band VII.) at the extreme violet end of the spectrum. 

 On increasing the height of the column to about six 

 inches, the bands I., II., IV. will be seen to have 

 become broader and darker, and the bands V., VI., VII. 

 to have coalesced so as completely to cut off the spec- 

 trum to the right of the line F in the blue ; a new 

 band (band III.) rather broad but faint, will be seen at 

 the junction of the yellow and of the green a little to 

 the right of the line D. 



By this means it is possible to ascertain that the 

 spectrum of chorophyll presents seven distinct absorp- 

 tion-bands. 



