CONTENTS 



Page 



History 1 



Etiology 1 



Source of the infection 1 



Experimental procedure 2 



General hatchery procedure 2 



Leavenworth hatchery 2 



Winthrop hatchery 3 



General laboratory procedure 3 



Results 4 



Leavenworth hatchery 4 



Winthrop hatchery 4 



Laboratory results 5 



I>iscussion and conclusions 5 



Addendum 7 



Literature cited 7 



111 



