500 Prof. W. B. Bottomley. Effects of Auximones on 



Two series of five dishes each were prepared containing solutions similar to 

 those in Series I and II ahove. The dishes were numbered from 1 to 10, 

 Nos. 1 to 5 forming Series I with Detmer's solution, and Nos. 6 to 10 Series II 

 with Detmer's solution plus complete water extract. Twenty uniform plants 

 ■of Lemna minor were placed in each dish, and the sets treated precisely as in 

 the preceding experiments for five weeks. Twenty average plants were then 

 counted out from each dish and the culture solutions in each series were 

 transposed ; that is, the five sets each of 20 plants previously growing in 

 Detmer's solution were now in Detmer's solution plus auximones (Series I), 

 while those hitherto supplied with auximones were now growing in Detmer's 

 solution alone (Series II). These plants were allowed to grow on for another 

 nine weeks, receiving the same treatment as to changing and counting as 

 [before. At this stage 20 plants from each series were again transposed, that 

 is, were transferred to their original solutions, and these were counted for a 

 further six weeks. The numbers in the five dishes of each series approxi- 

 mated very closely to the mean for the series throughout, so only the average 

 numbers are given in the Table below : — 



Table XII. 



Period I. 



Period II. 



Period III. 





Series I. 



Series II. 





Series I. 



Series II. 





Series I. 



Series II. 





— Auxi- 



+ Auxi- 





+ Auxi- 



— Auxi- 





— Auxi- 



+ Auxi- 





mone. 



mone. 





mone. 



mone. 





rnone. 



mone. 



At beginning 



20 



20 



i 



5th week (at 



20 



20 



14th week (at 



20 



20 









beginning) 







beginning) 









30 



46 



6th week ... 



49 



58 



15th week ... 



97 



89 



2nd „ 



64 



104 



7th „ 



102 



113 



16th „ 



402 



458 



3rd „ 



122 



235 



8th „ 



201 



201 



17th „ 



722 



957 



4th „ 



192 



630 



! 9*h „ 



688 



490 



18th „ 



1,704 



2,689 



5th ,. 



426 



1,528 



10th „ 



2,348 



1,212 



19th „ 



3,288 



5,606 









I 11th „ 



7,552 



2,956 



20th „ 



7,648 



14,720 









' 12th „ 



23,910 



6,707 















' 13th „ 



108,953 



23,142 















| 14th „ 



372,531 



73,318 









It is very evident from the above figures that whenever auximones are 

 present in the culture solutions the plants multiply much more rapidly than 

 in mineral nutrients alone. This is brought out by a comparison of the 

 final figures for each period. 



Period I. Detmer — auximones 426 Detmer-f auximones 1,528 

 Period II. Detmer + auximones 372,531 Detmer— auximones 73,318 

 Period III. Detmer — auximones 7,648 Detmer 4- auximones 14,720 



