16 



J. WILLIAM BUCHANAN 



TABLE lA 

 Head frcquencij — chloretone. In per cent 



PART NORM. T. OPHTII. T. MOR. ANOPH. HDL. DEAD 



3/4, '16. 10-mm. worms. Fed two days before cutting 



Control. 



1. M. 1/175. 



2. M. 1/450. 



6 

 2 

 



18 



10 







10 

 



3/14, '16. 15 



mm. worms. Fed two days before cutting 



Controls. 



3. M. 1/175. 



4. M. 1/450. 



4/22, '20. 16- 



to 18-mm. worms. Fed two days before cutting 



Control. 



5. M. 1/450. 



data show very clearly that the head frequency in A pieces is 

 decreased and in C pieces increased by reason of exposure of these 

 regions of the same animals to the concentration of chloretone 

 for the same period of time. This striking difference in results 



