4 BULLETIN 431, U. S. DEPARTMENT OF AGRICULTURE. 



tion, partially drying the larvae until mummified. These larvse of the black-brood 

 type gave a negative result both in microscopic examination and in the usual bac- 

 teriological culture experiments. Bacteria seem to take no part in this disease, and 

 so far as I have come in contact with black brood, I have been able to reach no certain 

 opinion as to its cause. [Translation.] 



It is very probable that the disorder encountered by Burri 7 which 

 was free from bacteria, was sacbrood. Out of 25 samples examined 

 between 1903 and 1905, he found four samples containing this dis- 

 ease alone, while in a few of the samples the disorder was accom- 

 panied by one of the other brood diseases. 



Kursteiner (1910), of Switzerland, gives a summary of all samples 

 examined by Burri and himself from 1903 to 1909. Out of 360 

 samples of suspected disease examined, 94 were diagnosed as "dead 

 brood free from bacteria." These were probably samples of sac- 

 brood. As shown by his later reports, Kursteiner has continued to 

 find this disease in the examination of suspected samples. 



The foregoing references to the literature show that beekeepers in 

 different countries had been observing dead brood in their apiaries 

 which was unlike brood dead of "foulbrood." On this point all of 

 the observers practically agreed. No name had been given to the 

 disorder. 



NAME OF THE DISEASE. 



Before 1912, very little definite information concerning this 

 somewhat mysterious disorder of the brood had been obtained. 

 After discovering its cause and determining its true nature, the 

 writer (1913) used the name " sacbrood" to designate it. The 

 name was coined to suggest the saclike appearance of the dead larvae 

 in this disease at the time they are most frequently 'seen by the bee- 

 keeper. 



The fact should here be emphasized that sacbrood is not a new 

 disease. It is only the knowledge concerning the disease and its name 

 that is of recent origin. It is far better, and in all probability much 

 more accurate, to think of sacbrood as a disease which has affected 

 bees longer than history records the keeping of bees by man. The 

 disease, therefore, has been collecting its toll of death for centuries, 

 often unawares to the beekeeper. Simply knowing that there is such 

 a disease should not be the cause of any additional anxiety concern- 

 ing its losses. On the other hand, less fear should be experienced, 

 since by knowing of it hope may be entertained that the losses resulting 

 from it may be reduced. 



PICKLED BROOD. 



The term " pickled brood" was introduced into beekeeping litera- 

 ture 20 years ago (1896), by William R. Howard of Texas. The 

 condition which he described under this term he declared was caused 



