TRUE & HARVEY: ABSORPTION OF CALCIUM SALTS 511 



Table 3 



Net Absorption by Squash Seedlings in Solutions of Calcium Chloride 



Original Concentration of 



Solution Grm. Norm. 



CaChXio-* 



Minimum Concentration of 



Solution as Grm. Norm. 



CaCl2Xio-6 



Maximum Net Absorp- 

 tion as Grm. Norm. 

 CaChXio-s 



4.3 grm. norm 38.5 grm. norm — 34.3 grm. norm. 



9.2 

 15-7 

 32.5 



53-5 



75-3 



116.5 



191. 8 



384.0 



582.4 



25-1 

 26.5 

 33-6 



42.7 

 20.5 

 19.7 

 19,9 



32.3 



141. 1 



- 15-9 



- 10.8 



- I.I 



+ 10.8 

 54-8 

 96.8 



171-9 

 351-7 



441.4 



seen in the solutions of CaS04 when compared with that seen in solu- 

 tions of Ca(N03)2 of a similar range of concentration, we are also 

 justified in concluding that the influence on process of absorption due 



to the CI anion is as favorable as that exerted by the NO3 anion. 



Discussion of Results 



It seems clear that for both the squash and white lupine in the 

 seedling stage the calcium ion favors the absorption of ions. The 

 lupine while finding this ion necessary does not absorb it in as large 

 quantities as does the squash. The maximum requirement per cul- 

 ture of five seedlings of the lupine under the conditions of these experi- 

 ments is not over 175 grm. norm. X io~^ Ca(N03)2 and about 125 

 grm. norm. X io~^ CaS04.* 



The squash on the other hand reduces an original concentration 

 of 518 grm. norm. Ca(N03)2 X io~^ to 47.8 grm. norm., thus finding 

 but a very small surplus present, and may absorb more than 700 

 grm. norm, when a concentration of 867 grm. norm. X io~^ is offered. 

 It is more quickly satisfied in the case of CaS04, this plant absorbing a 

 maximum of about 120 grm. norm, only from solutions increasing in 

 concentration up to about 825 grm. norm. X io~^. It takes in there- 

 fore from an excess supply about as much CaS04 as does the lupine. 



This comparison gives additional evidence of the well-known 

 indifference of the white lupine toward calcium in several combinations. 



From the evidence at hand it appears that in the presence of the 

 Ca ion, the effect exerted by the NO3 and SO4 anions on absorption by 

 the lupines is not markedly different. With the squash the anion 

 effect comes strikingly to the front. The Ca ion accompanied by the 



' Calculated from True, R. II., and Bartlett, H. H. Am. Journ. Bot. 2: 262 and 

 265. 1915. 



