154 Empusa Muscae versus Miisca Domestica L. 



with Empusa Muscae." These resulted in a proUfic growth of Mucor 

 racemosus. Why, I wonder, the cautious expressions of "outward" 

 and "naked eye" appearances? One must instinctively ask: — ^Was 

 Empusa Muscae present, or did it only appear to be present ? A state- 

 ment of this most important fact is carefully avoided. Why ? 



Dr Bernstein thus adds his opinion : " There can be no doubt than 

 that Mr Hesse has succeeded in producing a growth, ingestion of the 

 spores of which results in the death of all the flies from Empusa Muscae.'''' 

 One cannot but feel greatly surprised at such a statement from the nature 

 of the research work quoted. 



After consultation with Dr Copeman and Mr Ramsbottom (of the 

 Nat. History Museum) the investigators, Dr Bernstein states, agreed 

 on this fact. Here I should wish to ask : — Did they agree on the fact 

 that the flies dead from Empusa Muscae were the flies used, or did they 

 merely agree that all the flies, presumably submitted for examination, 

 were dead from Empusa Muscael 



Dr Bernstein now steps in the breach and tries a number of experi- 

 ments. Cage 1 was not interfered with; Cage 2 received a paper 

 saturated with steriHsed syrup of cane su^ar ; Cage 3 received in addi- 

 tion a paper saturated with syrup containing the spores of Mucor 

 hiemalis supplied by Mr Ramsbottoija. Cage 4 contained a paper 

 saturated with syrup containing spores of Mucor racemosus, "which 

 had been cultivated on egg yolk from Empusa Muscae (sic). The 

 cages were kept in a warm room (in whose charge, or under whose 

 observation, we would gladly have seen stated). Abnormal changes 

 only occurred in Cage 4. In fourteen days 75 % of the flies were dead. 

 Mr Ramsbottom, examining one of the flies from this cage, expresses 

 his opinion that the manifestations were identical with those of Einpusa 

 Muscae. No fly died in the other cages from Empusa. 



The general conclusions are stated as follows: — "It would seem 

 then that there could be no doubt that the deaths of the flies in Cage 4 

 were due to a fungus indistinguishable from Mucor racemosus, but 

 which can be readily cultivated in great quantities from the bodies of 

 flies dead of Empusa Muscae." This is more correct; we note "from 

 the bodies of flies dead of Empusa"; what role did the Empusa play 

 therein ? 



Empusa Muscae spores under no circumstances have produced in 

 the cultures made by myself and many other workers anything else 

 but what belonged exclusively to that fungus ; certainly never anything 

 like Mucor racemosus. Mucor racemosus, or Mucor resembling what 



