110 



stage for a mucli longer time. Tlie author relates a case, which 

 Avas brought to his notice by Ur. F. V, Mizerow, of Ufa, of a 

 peasant in whose body the larvae remained, according to the 

 opinion of the physician who treated the case, from about 

 November 1909 to March 1910, causing during the whole period, 

 great pain and sickness with vomiting. From January 1910 

 onwards his faeces contained blood. The last physician to whom 

 the peasant applied ordered injections of a concentrated solution 

 of tannin, and during the two days following these injections 

 some 50 larvae of M. stabulans were passed, nearly all of which 

 were alive and were identified by the author. Even in the bowels 

 of quite healthy individuals where the larvae evidently cannot 

 live very long, they may cause by their movements and their 

 efforts to escape, great pain with symptoms of toxaemia, or so- 

 called " false typhus." These symptoms are provoked by the 

 mandibles of the larvae scratching and piercing the mucous mem- 

 brane of the bowels. In addition to the blood lost and passed 

 with the faeces, the numerous small wounds so produced on the 

 intestinal walls allow the various microbes and toxins of the 

 bowel-contents to pass into the blood. The author quotes several 

 cases described in the old and more recent literature on this 

 subject of illness caused by the presence of the larvae of Miiscina 

 stabidans in the body. In some cases there is no doubt that the 

 larvae which have been passed by the patients belonged to this 

 fly, as the physicians who describe the cases were able to breed 

 the fly from the larvae. In other cases where the larvae passed 

 have been attributed to other flies the author is of opinion that 

 the diagnosis was probably erroneous and that in most of the 

 cases described they were those of Muscina stabulans. 



The author gives a detailed description of Muscina stabidans 

 and of its habits, and points out at length the differences between 

 the eggs of this fly and those of Musca doviestica, as well as of 

 two other flies commonly found in human dwellings, CaUiphora 

 erythrocephala and Fannia canicularis, all of the eggs being 

 figured. Muscina stabidans may lay as many as IGO small eggs, 

 spreading them singly or in lines over the whole surface of the 

 object on which they are laid, which makes them more diflficult 

 to recognise than those of other flies. According to the author 

 the larva of Mtiscina stabidans is very similar to that of Musca 

 domestica and Hydrotaea dentipes, the difference consisting 

 chiefly in the structure of the posterior stigmata and in the form 

 of the breathing apertures enclosed in them. With regard to the 

 mandibles of the larva, the hooks of which are very strong and 

 so closely pressed together in the third stage that they appear 

 as one hook, the author points out that in the second stage of the 

 larva the hooks are widely separated from each other. The seg- 

 ment next to the head of the larva has on both sides of its forward 

 end a rather wide stripe consisting of thin black lines of different 

 lengths. These lines under strong magnification appear to con- 

 sist of very small triangular spikes which evidently allow the 

 larva to keep its head segment in the body of its victim while it 

 is devouring it. The author confirms the statement of Bouche 

 that this fly is able to go through all its transformations in about 

 a month, thus being able to produce several generations during the 

 summer. 



