56 



Lewis Knudson 



of the plants varied directly with the concentration of the sugar, except 

 in the case of the culture containing 0.8 per cent of maltose, in which 

 the dry weight per plant is not in agreement with the normal results, 

 due to the fact that only four plants were present in the culture. The 

 results are given in table 23. 



EXPERIMENT WITH VETCH 



The experiment with vetch was conducted similarly to the preceding 

 experiments. Unfortunately the cultures containing the lower concen- 



TABLE 24. 



Influence of Various Concentrations of Maltose and of Lactose on 

 Growth of Vetch 



(Duration, twenty-four days) 



Culture solution 



Plant 



Length 

 of tops 

 (centi- 

 meters) 



Length 

 of roots 

 (centi- 

 meters) 



Total 



dry 



weight 



(milli- 

 grams) 



Gain 



or loss 



in weight 



(milh- 



grams) 



^1 



Check (no sugar) \ 



1 2 



{I 

 {I 

 {I 

 [1 

 {I 

 {I 

 [1 

 {I 

 {I 

 [1 

 [1 

 {I 



15.5 

 25.0 

 23.0 

 26.0 

 22.0 

 26.6 

 28.0 

 26.0 

 34.0 

 34.0 

 28.0 

 27.0 

 21.0 

 33.0 

 29.5 

 33.0 

 31.0 

 25.0 

 30.0 

 27.0 

 29.5 

 31.0 

 29.5 

 28.0 



10. 0\ 

 11.0/ 

 20.0) 

 22.0/ 

 21. 0\ 

 19.0/ 

 18. 0\ 

 14.0/ 

 14. 5\ 

 11.5/ 

 10. 0\ 

 12.5/ 

 8.5\ 

 8.1/ 

 18. 0\ 

 17.0/ 

 15. 0\ 

 19.0/ 

 10, 0\ 

 22.0/ 

 19. 0\ 

 18.0/ 

 19.01 

 15.0/ 



50 

 48 

 68 

 70 

 73 

 67 

 76 

 70 

 67 

 74 

 73 

 77 



—10 

 —12 



Maltose < 



1. 

 . 4 per cent • • 



. 8 per cent • • 



1 1 



1 . 5 per cent -! 



[2 



2 . 5 per cent 



+ 8 

 + 10 

 +13 

 + 7 

 +16 

 +10 

 + 7 

 + 14 

 + 13 

 + 17 





1 1 





1 per cent \ 2 



Lactose 



3 





( 

 1 





2 per cent ■ 



2 



