EUROPEAN FOULBROOD. 7 



Later the dead larval remains assume a brownish tint which 

 deepens to varying shades as decay continues and drying takes place. 

 During the early part of the decay, the firmness of the body wall per- 

 mits the removal of the larva intact from the cell. Later, however, it 

 offers but little resistance and is easily ruptured. The decaying mass 

 before di7ing often attains a certain amount of viscidity. Sometimes 

 it is of a doughy consistency, at other times it is purulent or sputum- 

 like, while at times it assumes a viscidity that will permit of its being 

 drawn out to the extent of an inch or more. When the larval mass 

 becomes dry it forms an irregular scale, usually brown in color, lying 

 on the floor or side wall of the cell or both, but not adhering closely 

 to them. 



GBOUP 3 



A lar^a dying of European foulbrood after being capped may be 

 found occupying one of many positions within the cell (PI. IV, 

 C, D, E ; PI. V, D, E, F, G, H). Dying before the two-day quiescent 

 period that precedes pupation, the remains during decay and as a 

 scale resemble in manj' respects those of larvaj described in group 

 2. The dry scales occupy usually an irregular position on the floor 

 of the cell (PI. IV, F, G). Dying during the two-day quiescent 

 period, however, the scales (PI. V, F, I) resemble very much those 

 of larvae dying at the same age of American foulbrood. The larval 

 mass assumes the brownish hue which deepens as the decay advances, 

 reaching a dark brown. Viscidity is present in the decaying larval 

 mass, but the extent to which the decaying material may be drawn 

 out is less than in American foulbrood. The scale is less brittle and 

 more rubberlike. 



At no time has the writer observed pupse dead of European foul- 

 brood. If they die of the disease it is a rare occurrence. 



The removal of larvae sick or dead of the disease is accomplished 

 to a greater or less degree by adult workers. The larvae are either 

 partially or entirely removed. This is usually done piecemeal. In 

 an infected colony will be found, therefore, the remains of larvae of 

 different ages (PI. IV, B) and (PI. V, A) in varying numbers. 



ETIOLOGY 



PREDISPOSING CAUSES 



Age. — Infection in European foulbrood takes place during the 

 feeding stage and at some time after the first day of larval life, 

 the larvae being more often 2 days of age, or older. Death takes 

 place somewhat more than 2 days from the time of infection. As 

 a rule, therefore, a larva has passed its fourth day of larval life 

 before death from European foulbrood occurs. From this age to 

 pupation larvae may die of the disease. The writer has not encoun- 



