410 



Mr Gustav Mann on the 



The differences in the breadth of the band, according to 

 the plant examined, are mainly due to differences in the 

 amount of chlorophyll developed in each plant, to the more 

 or less transparent character of the material examined, and 

 the amount of light used by the operator in his researches. 



The Second Band has the followins extent in — 



The Third and Toueth Bands appear only as absorptions, 

 and I was unable to define their extent ; but the third band 

 shows most absorption about X 616-6, and the fourth band 

 is darkest at X 578. 



The Fifth Band does not give very satisfactory results — • 



Spirogyra from X 531 —X 459 

 Ulva „ X 494 -X 460 (?) 



Trichomanes „ X 490-5 — X 469-5 = one leaf. 

 Asplenium „ X 499 —X 450 

 Hedychium „ X 560 —X 466 = two leaves. 

 The average = X 514-9 —X 460-9 



The Sixth Band is the least satisfactory — 



Spirogyra from X 459 — X 445 

 Asplenium „ X 445— X 436-5 



The average = X 452 -X 440-75 



Living chlorophyll shows therefore six bands, the two 

 first of which correspond to Kraus' band I., the third to 

 Kraus' band II., the fourth to Kraus' band III., the fifth to 



