xi, c, 5 Copeland: Growth Phenomena of Dioscorea 231 



Table III. — Growth of tubers of Dioscorea during one week, May 9-16. 



Col- 

 lege 

 No. 



Illumination. 









Growth 



in millimeters. 









Without soil. Tuber No. — 





In soil. Tuber 1 

 No.- 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



1 



2 



8 



952 



(Dark 



8 

 70 



14 



38 



2 

 5 



58 

 12 



3 



48 











77 

 15 



64 

 16 

 25 



111 



iLight... 



4 



27 

 15 



9 

 14 





1369 

 958 

 960 

 331 

 959 

 88 

 956 



1101 

 329 



1094 

 938 



(Dark 



(Light 













JDark... 



(Light 



32 





9 



9 



17 



19 



15 



309 



701 



58 



33 

 121 



580 



9 

 9 

 52 

 246 

 70 

 64 

 9 



324 

 788 

 21 





28 







40 



20 



288 

 419 



40 

 85 



6 







JDark . 



iLight 



35 



65 

 115 



2 

 329 







619 

 42 

 749 



191 



137 



57 



42 



(Dark 



109 

 15 

 17 



ILight 



43 



156 



717 



19 

 52 



399 

 22 



8 

 2 



8 



11 



338 



8 



13 



306 



JDark 



25 

 34 



286 



743 

 6 

 14 



244 

 23 



171 

 71 

 20 



50 



998 

 423 



906 



85 



44 



10 

 8 



(Light - _- 



5 



208 



6 



3 



185 

 21 

 769 



7 

 312 

 320 



6 



470 



262 

 11 



tDark - 



73 

 489 



29 



74 



(Light 



JDark 



(Light 



• 



160 



3 



161 







IDark 



ILight 



168 

 634 

 42 

 17 

 51 

 69 



17 



16 



116 



10 

 21 



10 



218 

 14 

 37 

 9 



330 



79 









262 

 122 

 60 



84 



344 

 149 



84 

 159 



23 

 8 



10 



103 



1 



64 



614 

 5 



61 



1 



IDark 





34 

 124 



159 



40 

 82 

 46 

 6 



(Light 



68 



JDark 





1 





9 

 10 

 24 



16 



7 



7 



20 



14 



16 

 86 



19 



JDark 







140 

 9 





1 









35 













During- the whole period of experiment, the plants exposed to 

 light reached a decidedly greater average length, as is shown 

 by Table IV. 



Table IV. — Length of longest shoot and average of most active plants. 





In light. 



In darkness. 



College 

 No. 











Longest. 



Average. 



Longest. 



Average. 





mm. 



mm. 



mm* 



mm. 



88 



3,860 



3,457 



1,690 



1,321 



329 



1,967 



1,324 



860 



534 



331 



4,780 



2,540 



1,900 



1.695 



938 



2,235 



792 



1,052 



672 



952 



722 



496 



682 



430 



956 



865 



790 



2,844 



924 



958 



2,591 



1,454 



919 



678 



959 

 960 



2,540 

 2,718 



1,455 

 1,371 



448 





2,150 



,1,160 



1094 



1,107 



963 



421 



375 



1101 



2,661 



2,010 



875 







1369 



L ... 



L900 



1,342 



1,130 



945 



