Influence of Certain Carbohydrates on Green Plants 53 



solution plus 1.2 per cent of agar and the sugar to be tested. A variety 

 of cabbage known as Wakefield was used, and the seeds were carefully 

 selected with regard to uniformity. The seeds were sterilized by immersion 

 in the hypochlorite solution for sixteen hours. An attempt was made 

 to sow in each tube twelve seeds, but this was not successful in aP cases 

 because of the haste necessary in sowing the seed so as to avoid danger 

 of contamination. The experiment was started on December 20, 1913, and 

 discontinued on February 18, 1914. The results with different con- 

 centrations of maltose are given in table 20: 



TABLE 20. Influence of Various Concentrations of Maltose on Growth of 



Cabbage 



(Plants grown in greenhouse. Duration, twenty-nine days) 



Culture solution 



Number 



of 

 plants 



Total 



dry 

 weight 

 (miUi- 

 grams) 



Average 

 weight 

 per 

 plant 

 (miUi- 

 grams) 



Maltose ■ 



Check (no sugar) < ^ 



( fl 



. 1 per cent s 2 



[3 



(1 



0.2 per cent^ 2 



[3 



. 4 per cent I 9 

 . 8 per cent . . . 

 1 . .5 per cent I ^ 



2 . per cent I „ 

 ,2.5 per cent. . . 



12 

 11 

 13 

 11 

 11 

 12 

 12 

 12 

 12 

 12 

 13 

 12 

 12 

 11 

 12 

 12 



95 



63 



98 



81 



90 



95 



86 



96 



112 



105 



126 



126 



150 



140 



134 



174 



7.9 



5.7 



7.5 



7.4 



8.2 



7.9 



7.2 



8.0 



9.3 



8.7 



9.7 



10.5 



12.5 



12.7 



11.2 



14.5 



6.9 



7.7 



7.7 



9.0 



9.7 



11.5 



11.9 

 14.5 



The table shows a progressive increase in the dry weight of the cabbage 

 with increase in concentration of maltose. At the lowest concentration 

 there appears to be a slight increase in dry weight over the check, but 

 the effect becomes marked only when a concentration of 0.4 per cent 

 is readied. 



