INTERNAL TEMPERATURE OF LEAVES. 



2fir 



Here the coloured leaf of Amherstia readies a temperature 

 2° C. higher than the leaf of Saraca. 



In the next table results are given of experiments with the 

 young red leaf of Mestia ferrea compared with the young leaf 

 of Saraca indica. The young leaf of Mesua ferrea is a little 

 stiffer than the leaf of Amherstia nohilis and is of a brighter 

 red, tending to pink rather than brown. 



Table XXVIII.— December 18, 1906. 



Here again the red leaf attains a higher temperature than 

 that of the pale leaf, this time to the extent on the average of 

 2-8'^C. 



In Table XXIX. are given the results of a comparison of 

 green and yellow leaves of Codiceum variegatum. This plant 

 as it grows in Peradeniya Gardens has some leaves almost 

 devoid of chlorophyll and of a bright yellow colour, others 

 green with chlorophyll , and there are leaves which show 

 proportions of the two colours, which form all the intermediate 

 stages between these two extremes. The cross sections of the 

 green and yellow leaves are of the same thickness, the cuticle 

 is of the same thickness and the cell arrangement is the 

 same. The difference is that the yellow leaves have few chro- 

 moplasts, and these are yellow, with a slight green tinge 

 when seen under the microscope, not green as in the green 

 leaf. 



