504 Physiologie. 



The authors publish a preliminary account of researches 

 tnade on the power of green plants to utilise carbon monoxide 

 with a view to the bearing of the work on Baeyer's theory 

 of photosynthesis. Their results are 1. plants of Tropaeolum 

 will thrive in an atrnosphere containing carbon monoxide 

 without a trace of carbon dioxide provided that the quantity 

 present exceeds the normal quantity of COl' in the proportion 

 of the relative solubilities of the two gases in water. Greater 

 quantities might be present even up to 70 per cent so long as 

 oxygen was present in normal amount. 



2. In bright sunshine a negative pressure is always obser- 

 vable in the bell jars containing plants growing in the monoxide, 

 the volume of oxygen exhaled being only half that given off when 

 the dioxide is supplied. 



3. Starch is formed in plants supplied with the monoxide 

 and exposed to sunlight. It was found in the leaves and in 

 the green stems, especially crowded around the vascular bundles. 



4. Seeds can be germinated and seedlings grown in an atrnos- 

 phere containing as much as 65"/o of carbon monoxide, organic 

 Compounds of carbon being formed during the process. 



Reynolds Green. 



Brown, H. J. an d Glendiunino, The velocity of Hydrolysis 

 of starch by Diastase. (Journal of the Chemical Society. 

 Vol. LXXXI. 1902. p. 388—400.) 



The authors have carried out several series of experiments 

 on the rate of change during the hydrolysis of starch by malt 

 diastase and come to the conclusion the process differs mate- 

 rially from the hydrolysis effected by dilute acids both as 

 regards the rate of change itself and the influence exerted 

 upon it by varying concentration of the Solutions. In these 

 respects they find that diastase agrees closely with invertase 

 as investigated by A. Brown and by Henri and they con- 

 clude with the latter observers that enzyme action, at any rate 

 in the cases of the two enzymes mentioned does not confirm 

 entirely to the simple law of mass action. Reynolds Green. 



COPELAND, E. B., Positive Geotropism in the Petiole of 

 the Cotyledon. (Bot. Gazette. Vol. XXXVl. July 1903. 

 p. 62 — 64. One figure in text.j 



Observations on the seedlings of Aesculus Californica, to 

 show that the downward curve executed by the petioles of the 

 cotyledon are in response to Stimuli recieved by the root tip. 



H. M. Richards (New York). 



Hill, Arthur Croft, n the r e v e r s i b i 1 i t y o f enzyme 

 action. (Journal of the Chemical Society. 83 — 84. [1903.] 

 p. 578.) 



In this paper the author gives a short summary of the 

 work previously published by him on the subject (Journ. Chem. 



