IV 



number of communications on these special subjects, 

 on which our knowledge is still sadly deficient. 



We have called attention to this matter before, but 

 it is of such importance that we do not hesitate to 

 repeat our remarks. 



P. L. S. 

 A. H. E. 



3 Hanover Square, 



London, W., 

 October 1st, 1909. 



