EXPERIMENT STATION BULLETINS. 



527 



and easily remembered names. Their onl}^ signiticauce is in indicating 

 wliere the diseases were first seriously investigated. It was particularly 

 desirable to change the name of the disease now known as European 

 foul brood, since "black brood" entirely fails to be descriptive and is 

 misleading." 



SYMPTOMS. 



**The presence of a particular disease in a colony of bees can be ascer 

 tained most reliably by a bacteriological examination, since the symp- 

 toms are somewhat variable. It is possible, however, to describe the 

 usual manifestations of the diseases, and the usual differences, so that 

 the beekeeper can in most cases tell which disease is present." 



AMERICAN FOUL BROOD. 



"American foul brood is frequently called simply 'foul brood.' It 

 usually shows itself in the larva just about the time that the larva fills 

 the cell and after it has ceased feeding and has begun pupation." 



Fig. 1. American foul brood: a, h, f, normal sealed cells; c, j, sunken cappings, showing 

 perforations; o, sunken cappings not perforated; h, Ij, m, n, q, r, larvae aflfected by disease; 

 e, i, p, s, scales formed from dried-down larvae; d, o, pupae affected by disease. Three times 

 naliual size. From Farmers' Bulletin 442, U. S. Dept. of Agr., Bureau of Entomology. 



"At this time it is sealed over in the comb (fig. 1, a, b, f). The first 

 indication of the infection is a slight brownish discoloration and the 

 loss of the well-rounded appearance of the normal larva (fig. 1, I). At 

 this stage the disease is not usually recognized by the beekeeper. The 

 larva gradually sinks down in the cell and becomes darker in color 

 (fig. 1, h, m), and the posterior end lies against the bottom of the 



