GOLDSTEIN: RESTING SPORES OF EMPUSA MUSCAE 323 
toplasm of a hyphal tube. This rounded mass of protoplasm 
becomes thick-walled and forms a resting spore. 
The term chlamydospore might be applied in the case of the 
Entomophthoreae to resting spores originating in any one of at 
least four different ways: 
1. The rounding up of the protoplasm in a hyphal body 
to form a rounded, thick-walled spore within the hyphal body. 
2. The swelling up of the tip of a hyphal filament to form 
a terminal, thick-walled resting spore. 
3. The formation of rounded, thick-walled spores at dif- 
ferent points along the hyphal filaments. 
e formation of rounded, thick-walled spores as buds 
arising either from a hyphal body or a hyphal filament. 
A clearer and more definite use of terms is much needed for 
these various cases. 
When the hyphal body itself becomes thick-walled forming 
an irregular thick-walled body the term “‘encysted hyphal body”’ 
alone should be employed. 
The term azygospore has been used in the Entomophthoreae 
not alone to designate a resting spore arising without a pre- 
liminary fusion of cells. It has been used also for spores borne 
at the tips of hyphae, formed along the hyphal threads, or 
arising as buds from hyphal bodies or filaments. Resting spores 
arising in all these ways, it seems to me, are merely asexua 
spores of typical chlamydospore type. 
In my opinion the term azygospore should be restricted to 
thick-walled resting spores arising from either of two sexual 
gametes which have failed to fuse. Such has been the use of 
the term in the mucors, where in many cases two gametes ap- 
proach each other, but do not fuse. Each or only one of the 
gametes then forms a thick wall and becomes an azygospore. 
The resting spores of Empusa Muscae are relatively large, 
thick-walled bodies. They are generally well rounded, and are 
multinucleated. They are approximately 304 in diameter. 
Oval spores generally measure 21 X 30 u. 
I have no evidence to show that a pairing or fusion of nuclei 
takes place within these resting spores, although in many spores 
the nuclei do appear to be arranged in pairs. There is no evi- 
dence of either a reduction or an increase in the number of nuclei 
contained within a young spore as compared with a more mature 
