90 



and repeated cultures from the dead flies yielded only Mucor racemosus. 

 To remove the difficulty that the food supplied might have only 

 stimulated the growth of Empusa spores already dormant in the 

 bodies of the flies, two groups of flies were fed on syrup containing 

 spores of Mucor hiemaUs and Mucor racemosus respectively, and all 

 died with the usual signs of Emjpusa mvscae as the cause. The controls 

 lived on and died naturally without exhibiting any such signs. Hesse's 

 observations are thus confirmed. Trials have been made of fly-papers 

 smeared with syrup infected with spores of M. racemosus and the 

 impression was that a marked increase of fly mortality took place. 

 Manure containing larvae was sprinkled with the same syrup and 

 none of the larvae matured. 



Ramsbottom (J.), iii. An Investigation of Mr. Hesse's Work on the 

 supposed Relationship of Empusa muscae and Mucor racemosus, 

 pp. 31-32. 



An account of the cultivation of spores of Empusa muscae is given 

 and it is stated that, so far as these preliminary observations go, they 

 show that a single Empusa spore, on germination, has never given rise 

 to the mycelium, or eventually the fruit of Mucor racemosus ; that 

 where such have occurred in a culture, the mycelium could usually 

 be traced to a cluster of spores which might easily have had the smaller 

 spores of Mucor in their midst. Penicillium and Eurotium occurred 

 in one or two cases, but the almost invariable appearance of Mucor 

 racemosus in most of the hanging-drops calls for further investigation . 



Hewitt (C. Gordon). Observations on the Feeding Habits of the 

 Stable Fly, Stomoxys calcitrans, L. — Trans. R. Soc. Canada, Ottawa, 

 (3), viii, September 1914, pp. 37-42, 1 pi. [Received 3rd 

 June 1915.] 



These observations, though incomplete, are published because any 

 addition to our knowledge of the habits of Stomoxys calcitrans is useful 

 at the present time. Reference is made to the work of Bishopp, 

 Mitzmain and Portchinsky [see this RevieuK Ser. B, i, pp.96, 113, 129 

 and 146-148]. Both sexes feed readily either on man or on guinea- 

 pigs, but the author found that feeding will not begin till at least 24 

 hours after emergence from the pupa, whereas Mitzmain found this 

 period to be 6-8 hours (in the Philippines). The processes of insertion 

 of the proboscis into the skin and of sucking the blood of the host are 

 described in detail. Flies fed on an average for 8 or 9 minutes. The 

 abdomen of the fully gorged fly is not only more than twice its usual 

 depth but half as broad again as the normal. In some cases, after 

 resting half an hour, the abdomen is again reduced to the normal size ; 

 digested blood first appeared in the faeces in about 6^ hours, the 

 average time required for digestion being 72| hours. These and other 

 similar data are set out in a table. Under the microscope the faeces 

 were found to contain haemoglobin crystals, and remains of leucocytes ; 

 no bacteria were found. The interval between meals is difficult to 

 determine, but the flies usually feed readily 48 hours after the last 

 meal ; one fly was very active in the laboratory 125 hours after 



