376 



BOTANICAL GAZETTE 



[may 



are very small. Thus, at the first break, in curve i, ^ = 9.605814; 

 while in curve 2, 3^ = 9.6056 at the common point of tangency 

 with curve 1. At this common point the two curves are only 

 0.000214 (per cent) apart. Similarly at the second break, for 

 curve 2, y = 20.01634, and for curve 3, ^ = 20.016284, a break of 

 only 0.000056 per cent. This combination curve runs remarkably 

 close to the data of observation and gives perhaps the best series 

 presented. The calculated and observed intake is shown in 

 table IX. Data in last column, table III. 



TABLE IX 



Algebraic curves for absorption data; intake in per- 

 centage OF AIR-DRY WEIGHT (XatlthtUtn), 5° C 



Time (minutes) 



5 



IO 



*5 



45 

 60 



90 



120 



ISO 

 180 



240 



300 



360 



420 



54o 



Data low 



I.64 



4-97 



8.77 



12.50 



17.77 



38.56 



Computed 



1.86 



3-44 



4.98 

 6.21 



8.89 



10.82 



12.51 



1542 

 17.86 



19.96 



21.86 



25.41 

 28.67 



31.67 

 3446 

 39.46 



~/ 



Data high 



6.22 



15 -43 



19.99 



2542 



34-55 



given similar ti 

 data as follows: 



Xanthium seeds at 20 and 35 C. were 

 Two equations were used for the 20' 



(1) ^=23.77 log I0 (o.o88x+i) + 1.524 



(2) y=57i3 log™ (o.oi32*+i)+6.6i6 



tangent 



equal for x = 34. 52, at which point 

 curve 1 has y = 15 . 931972, and curve 2, y = 1 5 . 931732, only o* 00024 

 per cent apart. 



In the 35 data, also, two successive equations were used: 



(1) y=3492 log IO (o.0983X+i)-£i.40 



(2) >'=73-05 logio (o. 0286X+ i)-f 6.53 



