36 



Lewis Knudson 



TABLE 13. Influence of Various Sugars on Growth of Vetch in the Greenhouse 

 (Duration, sixty-three days. Weight of seed, 30 milligrams) 



Culture solution 



Culture 

 number 



Number 



of 

 plants 



Total 



dry 



weight 



(milli- 

 grams) 



Average 



dry 

 weight 



per plant 

 (miUi- 

 grams) 



Gain in 



weight 



per 



plant 



(mim- 



grams) 



[1 



Check (no sugar) \ 2 



13 



Saccharose, 2 per cent < ^ 



[1 

 Maltose, 2 per cent ^2 



U 

 Lactose, 2 per cent 



73 



83 

 85 

 71 

 81 

 70 

 84 

 74 

 82 



5 

 4 

 2 

 3 



4 

 4 

 4 

 4 

 3 



348 

 298 

 157 

 499 

 646 

 477 

 464 

 406 

 300 



70 

 74 

 78 

 166 

 161 

 119 

 116 

 101 

 100 



40 

 44 

 48 

 136 

 131 

 89 

 86 

 71 

 70 







Fig. 4. influence of sugar on vetch 



81, Saccharose; 82, lactose; 83, check (no sugar); 84, maltose; 



85, check (no sugar) 



Notes were taken on 

 the lengths of roots 

 and tops, but the root 

 length and the height 

 of tops varied with the 

 degree of branching. 

 Consequently the 

 figures obtained are 

 not indicative of the 

 vigor of the plants. 

 The differences in the 

 cultures were easily ob- 

 servable, as is shown 

 by representative cul- 

 tures in figure 4. 



All the plants were 

 tested for starch and 

 also for reducing sug- 

 ars. No starch was 

 found in any of the 

 plants, but in those 



