TRUE & HARVEY: ABSORPTION OF CALCIUM SALTS 511 
TABLE 3 
Net Absorption by Squash Seedlings in Solutions of Calcium Chloride 
Original Concentration of Minimum Concentration of Maximum Net Absorp- 
Solution Grm. Norm. Solution as Grm. Norm. tion as Grm. Norm. 
CaCh X10 CaCle X 10-6 CaCle X 10-8 
ABQ EO LIM MOLIN e r5 ale) os 255.1 - 36:5 Stil) NOMS... — 34.3 grm. norm. 
ae ae ~~ se “a “cc aa 
9.2 eae 25.1 ae ier ee — 15.9 
LS a7hy 6 to tg geht eee Oe Een a 26.5 1 nae ey On mem 
ae “ee “a ac ae 
Bonptere bl celts, Sak xs 33. CRs ieee Pan ea. hee = Tet 
ae “ee se ae “c 
Seb) a ee eee A he Pah PENT + 10.8 
oe oe ~ ae ae aa 
75-3 eh Re axceeeeae ZO et ete Mere ees 54.8 
TOA? SYM as ik eee eee LOu7) | os ites tod ate 96.8 “ : 
191.8 . . Sy eae 19.9 men zn SopeN ote T7100 oe: 
FLY SPE ee eee 32.3——— Eee S57 mae 
5o240 hgh s ae k PAT piacere tlc Sey 441.4 “ 
seen in the solutions of CaSO; when compared with that seen in solu- 
tions of Ca(NOs)e of a similar range of concentration, we are also 
justified in concluding that the influence on process of absorption due 
to the Cl anion is as favorable as that exerted by the NO; 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 10-® Ca(NOs3)2 and about 125 
grm. norm. X 10-® CaSQ,.’ 
The squash on the other hand reduces an original concentration 
of 518 grm. norm. Ca(NOs3)2 X 107* 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 10~° is offered. 
It is more quickly satisfied in the case of CaSOu,, this plant absorbing a 
maximum of about 120 grm. norm. only from solutions increasing in 
concentration up to about 825 grm. norm. X 10-°. It takes in there- 
fore from an excess supply about as much CaSQ, 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 NO; and SO, 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 
3 Calculated from True, R. H., and Bartlett, H. H. Am. Journ. Bot. 2: 262 and 
265. I915. 
