320 GOLDSTEIN: RESTING SPORES OF EMpusA MUSCAE 
to be the resting spores of the fungus. Each spore contained a 
large globule of oil in its centre, and was surrounded by a layer 
of protoplasm. He added that these were seen by Brefeld, who 
considered them to be identical with conidia. 
I have found such irregular cells on the exterior of the fly’s 
body and believe them to be plasmolyzed or dried conidial cells 
or perhaps portions of the conidiophores which have become 
dried up or shrunken and appear thick-walled. I have found 
such cells, not only in the external mass of shrunken conidiophores 
of dried house flies which contain perfectly formed and rounded 
resting spores, but also in the external mass of conidiophores of 
very dry blue bottle flies attacked by Entomophthora X (Riddle), 
whose abdominal cavities contain fully developed, rounded 
resting spores with the characteristic bullate processes on their 
outer walls. 
It is worth while to review Winter’s observations more care- 
fully. He reported that he found dead flies attached to a 
window, most of which showed only the conidial stage, and he 
identified these conidia as belonging to E. Muscae. Three of 
these flies contained a mycelium in their body cavities. From 
the hyphae rounded bodies arose either as lateral or terminal 
swellings. These rounded bodies upon maturing were colorless, 
rich in oil drops, and covered with a uniformly thick membrane. 
They measured 30-50 yu in diameter. Brefeld’s only reference 
to Winter’s observations is in a footnote; this states that Winter 
found resting spores in several flies and believed them to be the 
spores of E. Muscae. 
It does not seem altogether improbable that Winter may have 
seen the resting spores of E. Muscae. However, since no 
cytological study of the fungus was made and since no drawings 
were given, his statements have remained under question. 
Lakon, in his paper on the wintering of E. Muscae, concludes 
that, since Winter found the resting spores once, resting spores 
must exist in this fungus, although no one since Winter has been 
able to find them. He adds that it is well known that the 
disease can occur upon other related flies. He suggests the 
importance of searching for the resting spores on other species 
of flies which are supposed hosts of E. Muscae. 
