THE NEPHRTDTA OF LEECHES. 565 



use of other methods has been absurdly inadequate to the 

 problem he set himself to solve. 



A comparative study of the nephridia of leeches and of M. 

 Bolsius's views anent them may well serve as a startling 

 vparning of the danger incurred in zoological research by 

 paying too great attention to serial sections while neglecting 

 the older and all-important methods. My desire to formulate 

 this warning and to emphasise it by reference to a very 

 striking example is ray excuse for having given so much atten- 

 tion to M. Bolsius. 



A. G. Bourne. 



The Pkesidency College, Madras ; 

 September 12th, 1892. 



