by Green Plants from certain Organic Compounds. 163 



As would be expected, those plants which had been deprived of 

 starch by keeping in the dark were considerably longer showing 

 starch formation in their leaves than those which had been brought 

 into a similar condition under the bell-jars by the absence of carbon 

 supply (C0 3 ), although plants as nearly as possible of the same age 

 and size were originally selected, and in each case used for the 

 cultures as soon as they Were found to be completely free from starch. 



A few of the most nearly comparable results as to the time 

 required are given below. 



Plants in Culture Solution + 1 per cent. Glucose. 



Plant. 



Starch first detected in leaves after the 

 lapse of 



Cheiranthus Cheiri (deprived of starch 

 by absence of C0 2 ), 5 plants, A, 

 B,C 



Cheiranthus Cheiri (deprived of starch 

 by placing in dark), 2 plants, C", D 



Note. — About 7 hours in dark be- 

 tween 1st and 2nd day. 



(A) 13 hours (continuous)^ 



(B) 11 „ 



(C) 13 „ „ from time 



■ of placing 



(C) 13 hours 1st day ; 8 in culture 



hours 2nd day solution. 



(D) 13 hours 1st day; 10 



hours 2nd day J 



No. 4. Experiments with Aldehyde (Acetic). 



The aldehyde was purified in the usual way by saturating an 

 ethereal solution of commercial aldehyde with gaseous ammonia 

 collecting the crystals, and distillation with dilute H 2 S0 4 . 



The aldehyde ammonia used was a portion of th'at obtained in 

 above ; the crystals would be pure. 



A. On Cut Branches. 



Solution used. 



Plants. 



Be suits. 



Culture solution + 

 075 per cent, alde- 

 hyde 



Culture solution + 

 (rl per cent, alde- 

 hyde (sand culture) 



Ranunculus acris 

 Acer pseudoplatanus 

 Scrophularia aquatica 

 Alisma plantago 



B. Solution supplied to R 



Phaseolus vulgaris 

 JPhaseolus multijlorus 

 Euphorbia helioscopia 

 Cheiranthus Cheiri (3 plants) 



No starch formed (5 

 days) ; leaves unhealthy 

 towards end of experi- 

 ments. 



DOts. 



No starch formed (6 

 days) . 



VOL. XLV1I. N 



