by Green Plants from certain Organic Compounds. 171 



(b.) More "soluble starch" added to the culture solution in each, 

 of the above till solution contained about 7 percent. " soluble starch," 

 and experiments continued for another six days with same plants. 



Same plants. No starch formed. 



No. 11. Experiments with Glycogen. 



An ordinary solution of glycogen obtained by extracting the liver 

 of a freshly-killed rabbit was purified by CI. Bernard's* method, in 

 which the glycogen is first precipitated by alcohol and the well- 

 washed precipitate (with alcohol) dissolved in strong potash and 

 boiled for half an hour. The solution is then diluted, filtered, and 

 again precipitated in alcohol, well washed with the same, and the 

 precipitate dissolved in water. The aqueous solution is strongly 

 acidified with acetic acid (to render the insoluble (in alcohol) potas- 

 sium carbonate soluble as potassium acetate), finally precipitated with 

 alcohol, well washed with the same, and dried at a low temperature. 

 If kept for any length of time after the preparation, the dry powder 

 was thoroughly washed with alcohol and again dried before making 

 the solutions used in the experiments. 



The solutions remained opalescent and did not contain any 

 " reducing substances " after the experiments ; this was proved by 

 precipitating the glycogen, &c, with strong alcohol and testing the 

 filtrate after evaporating off the alcohol, &c, &c., in the usual way. 



No. 11. — Experiments with Glycogen. 

 A. With Cut Branches. 



Jution used. 



Plants. 



Results. 



Iture solution 

 • 5 per cent, 

 ■ogen 



Alisma plantago 

 Ranunculus acris 

 Epilobium hirsutum 



No starch formed (6 

 days). 



Leaves not apparently in- 

 jured. 





B. Solution supplied to Roots. 



The culture solution 

 + 1 per cent, gly- 

 cogen. 



Acer pseudoplatanus 

 Phaseolus vulgaris (2 plants) 

 Cheiranthus Cheiri (4 plants) 



No starch in the leaves at 

 end of 6 days. 



The plants were not apparently injured, and resumed growth on 

 being lanted out. 



*' Hoppe-Seyler, ' Traite" d' Analyse Chimique appliquee a la Physiologie. 

 Pi 587 (Translation from G-ermanj, pp. 147 — 148. 



YOL. XLVII. 



