ZANDER, AUGUST, 1909. 89 
2. The evidence obtained indicates that the disease is infectious. 
3. An organism was encountered in a number of diseased bees, to 
which Malden gave the name Bacillus pestiformis apis. 
4. This organism was not proven by Malden to be the cause of 
the disease. 
ZANDER, AUGUST, 1909. 
In 1909, Dr. Zander, at Erlangen, Germany, wrote an interesting 
paper + concerning the cause of a disease affecting the adult honey 
bee. 
“ From his studies Zander was led to believe that there are two 
forms of dysentery. One form he considers to be noninfectious and 
comparatively harmless. The cause of this form is attributed to 
various conditions, such as disturbance of the colony, queenlessness, 
improper winter stores, deficient opportunity for a cleansing flight, 
etc. A second form of dysentery Zander refers to as the malignant 
form. In referring to the virulence of this form Zander says that it 
has all the characteristics of an infectious disease, destroying more 
colonies in one spring in the neighborhood of Erlangen than foul 
brood had durmg the entire preceding year in the whole State of 
_ Bavaria. 
During his investigations in 1907 Zander found in the mid-éut of 
diseased bees a protozoan to which the name Nosema apis was given. 
This portion of the intestine of all the bees which died of the ‘ viru- 
lent’”’ form of dysentery was found to be milk-white and completely 
-filled with Nosema spores. Queens from dysenteric colonies were 
examined and found also to be infected with the protozoan. No 
drones were found infected. This was supposed to be due to the fact 
that there are no drones during the active dysenteric season. The 
excrement from the bees also contained numerous spores. 
Zander expresses the belief that the transmission of the disease is 
made possible by the deposit of excrement on the frames and walls of 
the hive, which takes place when no opportunity is afforded the bees 
for a cleansing flight. The mutual feeding practiced by bees hastens, 
it is suggested, the spread of the infection. The bees are supposed 
to be subjected to further infection from without on account of the 
spores that are spread about through the medium of the excreta of the 
flymg bees. Robbing also is given as a fruitful means of transmission. 
The use of contaminated combs from apiaries in which the infection 
is present is also thought to be a means for the spread of the disease. 
The prognosis is supposed to depend somewhat upon conditions. 
Long, hard winters are given as a cause of very heavy losses with this 
disease. If, on the other hand, the spring is warm with a good flow 
1 Zander, Dr. Enoch, August, 1909. Tierische Parasiten als Krankheitserreger bei der Biene. Miinche- 
ner Bienenzeitung, Heft 9. Pp. 11. 
