66 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



covering the positions of the three absorption-bands Nos. II, 

 III, and IV only. 



Blue. — This has the red greatly subdued in consequence 

 of a broad absorption-band exactly corresponding in position 

 with the chlorophvllian band No. I. Another occurs to the 

 right of it, but not in the position of No. II. The whole of the- 

 more refrangible half is transmitted, so that all the chlorophyllian 

 bands excepting No. I will be included. 



When the light is examined with the spectroscope, after 

 passing through each of the coloured glasses as well as a dark 

 green solution of chlorophyll, one quarter of an inch in depth,, 

 the following are the results : — 



With red glass, there is a band of red sharply separated from 

 a band of green by the dark absorption-band No. I. 



With yellow glass, a yellow band is intercalated between the 

 absorption-bands No. I and No. II. 



With green glass, there is only a green band of light over- 

 spreading the positions of the feeblest absorption-bands, Nos. Ill 

 and IV. 



With blue glass, there is a narrow red band, then a very- 

 broad dark absorption-band. This is followed by a second to the- 

 left of the d line. All the most refrangible end is absorbed, 

 including the bands V, VI, and VII. 



Experiment No. I. 

 Gcrminatin g Mus tard. 

 Three grammes weight of Mustard- seed was sown under each 

 glass on May 4, 1889. Three other grammes were perfectly 

 dried, and they then weighed only 1*78 grammes. The dry 

 weight of the embryos separated from the testas was 1*24 

 grammes ; that of the testas being, of course, 0*54 gramme. On 

 May 29 the seedlings were taken up and weighed at once. 

 They were then perfectly dried, and the dry substance left, after 

 the evaporation of all water had taken place, was ascertained 

 The following table gives the results : — 





Mean 



Total weight 



Dry 



(lain (do.) 



Dry sub. 



Watfr 



& 



temp. 



(grs.) 



sub. 



(on embryo*) 



(!'■'••) 



(p.c.) 



82°P. 



41-52 



2-14 



•90 



515 



94 8" 



Y 



03° 



48*67 



4-29 



3-05 



8-81 



91-19 



G. . 



54° 



.'57-80 



2-86 



l-(>2 



7-5<; 



9244 



a 



56° 



83*56 



2 70 



1-46 



8-04 



91-90 



Cl ,. 



(50° 



85-47 



7-27 



C-03 



8-40 



01-54 



Open .. 



50° 



93-83 



8-45 



7-21 



9-10 



90*90 



