272 SCIENCE PROGRESS 



from control of the other factor of the environment. It would 

 be worse than useless to formulate any theories at the present 

 incomplete stage of the experiments." 



Here, then, we must perforce leave the matter, not, however, 

 without the expression of the hope that Mr. Beebe will be 

 enabled to continue these experiments, from which important 

 additions to our knowledge of the aetiology of colour-develop- 

 ment in birds are almost sure to eventually accrue. 



