

ON BALANTIDIUM COLI (MALMSTEN) AND 



BALANTIDIUM SUIS (SP. NOV.), WITH 



AN ACCOUNT OF THEIR NEURO- 



MOTOR APPARATUS 



A THESIS ACCEPTED IN PARTIAL SATISFACTION OF 

 THE REQUIREMENTS FOR THE DEGREE OF 



DOCTOR OF PHILOSOPHY 

 AT THE UNIVERSITY OF CALIFORNIA 



BY 



JAMES DALEY McDONALD 



1922 



