Physiologie. 211 



Ball, N. G., On the Action ofPectase. (Sei. Proc. Roy. Soc. 

 Dublin. XIV. 28. p. 349-357. 1915.) 



The eleclrical conductivity during the coagulation of pectin was 

 measured and found to remain practically constant shewing thal a 

 true gel is formed. 



A viscosimeter of the Ostwald type was used to determine the 

 changes in viscosity during coagulation, and experiments shewed 

 that the activity of the enzyme is greater at 14° than at 0° C. 



At first the viscosity increases slowly, then more rapidly, until 

 a maximum is reached, this being followed by a rapid decrease. 

 The maximum is lowered by increasing the electrolytes present and 

 raised b3^ decreasing them. The author considers the decrease in 

 viscosity to be due to the action of the electrolytes in clumping 

 together the particles of colloid forming the reticulum of the gel, so 

 that a Suspension is produced. Wm. B, ßrierley (Kew). 



Benjamin, M. S., A Note on the Occurrence ofUrease in 

 legume Nodules and other Plant Parts. (Proc. Roy. Soc. 

 New South Wales IL. 7. p. 78—80. 1915.) 



The presence of Urease has been determined in the root nodu- 

 les of seventeen out of twenty one species of Leguminosae investi- 

 gated. The enzyme is also present in various portions of other 

 plants examined and in certain Algae and Lichens; in the latter 

 case the reaction for the presence of the enzyme being particularly 

 pronounced and rapid. 



It is suggested that some correlation may exist between the 

 presence of Urease and the processes of elaboration and interchange 

 of nutritive material in the living plant. Wm. B. ßrierley (Kew). 



Böse, J, C, An Automatic Method for the Investigation 

 of Velocity of Transmission of Excitation in Mimosa. 

 (Phil. Trans. Roy. Soc. Lond. CCIV. B. 305. p. 63—97. 1913.) 



The author has investigated the phenomenon of excitation in 

 Mimosa and has devised a method whereby the value of the latent 

 period and the velocit}^ of transmission may be obtained by auto- 

 matic records made by the plant itself. This is made possible by a 

 new type of record in which the writer accurately tuned to a defi- 

 nite and known frequency is maintained in resonant Vibration. By 

 this device errors of friction and inertia are reduced to a minimum. 

 The apparatus is figured and described. 



Much experimental data is given which in the author's opinion 

 "proves conclusively that the transmission of excitation in the plant 

 is a process fundamentally similar to that which takes place in the 

 animal, being in the one case, as in the other, a propagation of 

 protoplasmic change". Wm. B. Brierley (Kew). 



Everest, A. E., The Production of Anthocyanins ofAn- 

 thocyanidins. (Proc. Roy. Soc. Lond. LXXXVII. 1. p. 444—452. 

 1914.) 



Consideration of work on the Anthocyan pigments of plants 

 leads the author to conclude "1) That if the Anthocyans are produ- 

 ced from the yellow glucosides, then it must be by some interaction 



