10 BULLETIlSr 804, TJ. S. DEPAETMEIST OF AGRICULTURE 



main in the cells for several days without being cleaned out. Also 

 more larvae nearly ready for pupation were being affected. Most of 

 these instead of remaining coiled were inclined to extend on the 

 lower side wall in a brownish gray, slimy mass and exhibited a ten- 

 dency to be viscid. At this stage of decomposition, when a stick is 

 inserted the mass forms a coarse granular band for a short distance 

 and then breaks so as to form droplike masses, but does not stretch 

 out in a fine thread. These larval masses dried down to rubbery 

 dark brown scales something like American foulbrood scales in ap- 

 pearance, but different in consistency. These scales could be removed 

 quite easily and would bend like a piece of partially granular old 

 rubber. They also lay irregularly placed in the cells, often spirally 

 extended, while American foulbrood scales are uniformly on the 

 lower side wall. The bacteriological explanation for this abnor- 

 mal characteristic will be discussed later under bacteriological 

 observations. 



The predominance of these rubbery masses and scales increased as 

 the disease progressed and the bees seemed to make little attempt to 

 clean them out, even after the queen was caged on the thirty-first 

 day, thus shutting off any increase of fresh larvse, or even after the 

 queen and all queen cells were removed on the thirty-seventh day. 

 On the thirty-ninth and also on the forty-first day, five and four 

 frames, respectively, of emerging brood and Italian bees were united 

 with this colony, but it was i^ot until a new Italian queen, confined 

 in a cage, had been hung in on the forty-fifth day that a final com- 

 plete cleaning up was made. 



This new queen was not accepted, however, and a young queen was 

 raised from the brood that was added to this colony, so that fur- 

 ther observations were ended here although the virgin queen was 

 killed and another Italian queen introduced. This colony was re- 

 ported healthy, however, about the middle of August. 



The hybrid bees seemed to lack ambition to fight the disease. 

 When combs were removed from the colony, the bees never were ob- 

 served to be working in the cells, and paid little attention to ma- 

 terial partially drawn from the cells and crushed. 



COLONY r 



Race. — Italian, possibly with some slight hybrid blood. 



Qiteen. — 1917, fairly good condition. 



Bees.— Workers, good color, fairly quiet, drones inclined to be darker. 



Condition of colony at tim& of infection. — Brood in three frames, a little 

 more than one-third sealed. Bees covering about six frames. Build- 

 ^ ing up well. Proportion of field bees to nurse bees about equal. 



Date of first infection. — May 31, 1918. 



Material used. — Ten diseased larvse from sample No. 5874, macerated 

 in 250 c. c. of a 50 per cent sugar sirup. 



'First appearance of disease noted. — June 4, 1918, four days after in- 

 fection. 



Age of larvae first attacked. — Four days after hatching from the egg. 



