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. 
