47 
“As stated, my first examination of this dead brood was 
The name “sacbrood” made in 190Z, when samples were, received diagnosed by 
beekeepers as ‘pickled brood.’ The fact was easily de- 
termined at that time that the disease could not be considered a tungous discase and 
was, therefore, not pickled brood. In the past my preference has been to refer 
to this condition only as the ‘so-called pickled brood.’ Since the disease is not. 
pickled brood, it will produce less confusion and be more scientific if the term 
‘pickled brood’ be entirely omitted in the name for the disease. Many larvae dead 
of this disease can be removed from the cell without rupturing their body wall. When 
thus removed they have the appearance of a small closed sac. This character sug- 
gested the name ‘sacbrood.’ The name has the virtue, therefore, of being both 
appropriate and brief. 
“The strength of a colony in which sacbrood is present is 
The symptoms of frequently not noticeably diminished. When the brood is 
sacbrood badly infected, however, the colony naturally becomes appre- 
ciably weakened thereby. The brood dies after the time of 
capping. The dead larvae are, therefore, almost always found extended lengthwise 
in the cell and lying with the dorsal side against the lower wall. It is not unusual 
to find many larvae dead of this disease in uncapped cells. Such brood, however, 
had been uncapped by the bees after it died. In this disease the cappings are fre- 
quently punctured by the bees. Occasionally a capping has a hole through it indi- 
eating that the capping itself had never been completed. A larvae dead of this 
disease loses its norma] color and assumes at first a slightly yellowish tint. ‘Brown’ 
is the most characteristic appearance assumed by the larvae during its decay. 
Various shades are observed. The term ‘gray’ might sometimes appropriately be 
used to designate it. The form of the larvae dead of this disease changes much 
less than it does in foul brood. The body wall is not easily broken’ as a rule. On 
this account often the entire larvae can be removed from the cell intact. The con- 
tent of this saclike larva is more or less watery. The head end is usually turned 
markedly upward. The dried larva or scale is easily removed from the lower side 
wall. There is practically no odor to the brood combs. 
“In the study of samples of this disease received directly 
The infectious nature from beekeepers no microorganisms have been found, either 
and cause of sacbrood culturally or microscopically, to which the cause of the dis- 
ease can be attributed. This fact, together with the fact 
that the disease often disappears without any great loss to the colony, would tend to 
indicate that the disease is not infectious. The experimental evidence which I have 
obtained proves, however, that the disease is infectious.” 
