20 



The following Paper has been received : — 



Dr. J. 0. MOTTRAM. 



An Experimental Determination of the Factors wliich cause 

 Patterns to appear conspicuous in Nature. 



The Publication Committee desire to call the attention of 

 those who propose to offer Papers to the Society, to the great 

 increase in the cost of paper and printing. This will render it 

 necessary for the present that papers should be coiidensed, and 

 be limited so far as possible to the description of new i-esults. 



Communications intended for the Scientific Meetings should 

 be addi'essed to 



P. CHALMERS MITCHELL, 



Secretary. 

 Zoological Society of London, 

 Regent's Park, London, N.W. 

 Airtnl lUA, 1916. 



