Prof. J. R. Green. Action of Light on Diastase. 



25 



established. — We have constantly obtained from the cerebellar cortex 

 a tonic contraction of either the triceps or biceps, or both together, if 

 the " acerebral " tonus had not appeared. 



H. Synchronous Excitation of the Cerebellum and Cerebrum. 



Synchronous excitation of the cerebral area for the fore limb and 

 the cerebellar focus has given so far, in cases where the cerebellum 

 is definitely excitable, an addition to the tonus elicited previously from 

 the cortex cerebri. 



While such reinforcement seems to be the rule, we believe that the 

 clonic character of the cortical impulses is adversely affected by the 

 cerebellar activity. 



Since Professor Sherrington's third note on " Reciprocal Innerva- 

 tion of Antagonistic Muscles " appeared, we have investigated the 

 question of reflex inhibition of the " acerebral " tonus by the graphic 

 method, to see how far the two effects are identical, and have obtained 

 some instructive results, the full discussion of which, however, must 

 be postponed, as the observations are incomplete. It is sufficient 

 now to say that while we have confirmed Professor Sherrington's 

 discovery that excitation of an afferent tract on the same {i.e., in our 

 experiments, right) side causes relaxation of the triceps and contrac- 

 tion of the biceps, we have also found that excitation of a left afferent 

 tract causes relaxation of the biceps and contraction of the triceps, an 

 interesting correspondence with the alternation we observed in the- 

 two halves of the cerebellum, and which is obviously related to 

 the movement of progression. 



>; On the Action of Light on Diastase and its Biological Signi- 

 ficance." By J. Reynolds Green, Sc.D., F.R.S., Professor 

 of Botany to the Pharmaceutical Society of Great Britain. 

 Received January 28, — Read February 25, 1897. 



(Abstract.) 



According to the observations of Brown and Morris,* the quantity 

 of diastase in foliage leaves undergoes considerable variations during 

 the twenty-four hours of the day, being greatest in the early morning 

 and least in the evening, particularly after several hours' sunshine. 

 During the past three years the author has carried out a series of 

 experiments to ascertain whether the diminution in quantity is due 

 to a destructive influence of the light upon the enzyme, similar to- 



* ' Jour. Ckem. Soc.,' May, 1893. 



