lo Jan., 1 910.] Bee Mortality in the Stawell District. 6r 



The microscopical examination showed the presence of yeast as fol- 

 lows : — - 



No. 1 sample ... ... ... Large yeast cells, budding. 



l> ,, ... ... A mass of yeast eells. 



,, 8 ,, ... ... ... Some yeast cells only. 



,, 4 ,, ... ... ... Pollen cells, no yeast. 



'On the primary agar cultures prepared from the colon and contents, 

 taken from the unhealthy bees, there developed at room temperature a mass 

 of fungoid growths, Penicillium glaucum, a number of yeasts, and a few 

 colonies of bacteria forming large wrinkled growths on the surface of 

 the media. On sub-culture on gelatine, however, they were early re- 

 cognised as belonging to the B. siihtilis group. The cultures plated out 

 ■on media from material from the healthy bees did not yield anything 

 •more than a few moulds and a mucor similar to Mucor racemosus. 



At this period it was realized that the information gained by the micro- 

 .scopic and bacterioscopic examination had not revealed anything to account 

 for the malady beyond the presence of a number of yeasts in the watery 

 .samples of honev' and cells somewhat of a similar nature in the colon 

 contents of the unhealthy bees. The presence of these cells in the 

 honey and also in the bees gave rise to a suspicion that the disease might 

 be caused by the bees feeding on honey in a state of fermentation. For 

 the purpose of further investigation, two additional samples were forwarded 

 by Mr, Beuhne, one taken from a healthy and the other from an imhealthy 

 Tiive. Some thin honey was received at the same time for examination as 

 to fermentative changes. A small number of yeast cells were present in 

 this honey. In the meantime my attention was drawn by Mr. Beuhne to 

 .an article in the " Leipziger Bienen-Zeititng," October, 1909, by Dr. Enoch 

 Zander, of Erlangen, on a disease of bees caused by an animal parasite, 

 which he has named Nosema apis. This parasite, he states, is always 

 present in bees suffering from a maladv somewhat similar to that under in- 

 vestigation, and the oval cells described by him exactly resemble those de- 

 tected previously in the chyle stomach. On an examination of the chyle 

 :stomachs from a number of bees received later, the cells previously re- 

 ferred to were again found to be present both in the sickly and in one 

 instance only in a bee supposed to be normal. From Dr. Zander's de- 

 scription of Nosema apis, the cells found resemble in every particular those 

 •mentioned in his article. His description is as follows : — 



The peculiarities of life and the form of Nosema apis are exceedingly simple. 

 Above all, it must be emphasized that this parasite and all its relations are cell 

 parasites, which can only thrive in living tissue, but not outside the bee's body. In 

 this respect it differs from the silkworm parasite which thrives in all organs, while 

 Nosema a-pis thrives only in the middle intestine. 



After having devoured the intestinal cells of its victim, it envelopes itself in 

 a membrane which protects it after the death of its host, and thus may live for a 

 considerable time outside the body of the bee. These forms are called spores and 

 are the only stages of development ever met with. If such a spore enters the middle 

 intestine of a healthy bee, the membrane splits open and e.xpels a minute elongated 

 parasite, which immediately bores into tlie intestinal walls and increases to an 

 incredible extent. Barely four days after entering the intestine it produces new 

 spores. The Nosema spores cause 'a marked discolouration of the intestine. While 

 in healthy bees it is reddish and translucent, it becomes dull and milky white in 

 colour after infection, a true sign of the disease. The intestinal cells which are 

 full of Nosema spores gradually die off and are excreted and thus give rise (o a. 

 possibility of affecting healthy bees should the excreta come in contact with their 

 food. 



