by Green Plants from certain Organic Compounds. 1 1)1 



The Calcium Salt of Lsevulinic acid. 

 A. On Cut Branches. 



Solution used. 



Plants. 



Results. 



The culture solution 



Ranunculus acris 



No starch formed (10 



+ 1 per cent, cal- 



Scrophularia aquatica 



days). 



cium laevulinate 



Alisma plantago 





B. Solution supplied to the 



Roots. 



Same solution as 



Cheiranthus Cheiri 



No starch formed in the 



above 



Quercus robur 



leaves (8 days). 





Acer pseudoplatanus 





Plants apparently uninjured, resumed growth, and had formed 

 starch again ( Acer) after 10 days from planting out. 



No. 7. Experiments with Saccharon {Cane-sugar). 



The saccharon used was pure cane-sugar obtained from Kahlbaum, 

 of Berlin ; it gave no reduction on heating with Fehling's solution 

 at 100° for ten minutes. Many specimens of ordinary cane-sugar 

 contain a considerable amount of glucose, and are obviously un- 

 suitable for such investigations. 



A. As A. Meyer and E. Laurent* have shown that starch is 

 formed by leaves., cut branches, &c, placed in the solutions of cane- 

 sugar, I did not repeat these experiments. 



B. Solution supplied to the Roots. 



Solution used. 



Plants. 



Results. 



Culture solution + 

 *5 per cent, sac- 

 charon 



Acer pseudoplatanus 

 Cheiranthus Cheiri (3 plants) 

 Phaseolus vulgaris (2 plants) 

 Euphorbia helioscopia 



Starch was formed at end 

 of 4 days in all the 

 leaves. 



Wishing to determine whether saccharon is as readily absorbed by 

 the roots of plants as glucose (compare No. 3, p. 162), I selected six 

 young plants of Cheiranthus Cheiri, as nearly as possible of equal 

 size, so that three of them were about the same weight as the other 

 three (a = three plants, B = three nearly similar plants ; B weighed 

 0*01 gram more than a) ; (a) were placed in a cylinder containing 

 100 c.c. of the culture solution -+- 0*5 glucose; B in a similar 



* Loc, cit. 



