INFORMATION TO SUBSCRIBERS 
SuBSCRTPTTONS at the rate of S5.00 per annum should be made payable 
to the National Academy of Sciences, and sent to Williams & Wilkins Com- 
pany, Baltimore, or Arthur L. Day. Home Secretary, National Academy of 
Sciences, Smithsonian Institution, Washington, D. C. Single numbers, $0.50. 
