﻿2 
  

  

  PROCEEDINGS 
  

  

  OF 
  THE 
  

  

  ROYAL 
  SOCIETY 
  OF 
  LONDON 
  

  

  Series 
  B 
  

  

  CONTAINING 
  PAPERS 
  OF 
  A 
  BIOLOGICAL 
  CHARACTER 
  

  

  VOL. 
  XCI. 
  

  

  LONDON: 
  

  

  Printed 
  for 
  THE 
  ROYAL 
  SOCIETY 
  and 
  Sold 
  by 
  

   HARFJSON 
  AND 
  SONS, 
  LTD., 
  ST. 
  MARTIN'S 
  LANE, 
  

  

  PRINTERS 
  IN 
  ORDINARY 
  TO 
  HIS 
  MAJESTY. 
  

  

  November, 
  1920. 
  

  

  