108 



(c) Essential oil of oranges 30 grms., liquid vaseline 120 grms. 

 The vaseline considerably delays the evaporation of the oil and 

 permits of the mixture retaining efficacy until the morning, 

 when the mosquito Avhich transmits yellow 'fever generally bites!" 



Mr. Eeynold has modified Sannartz' formula as to the propor- 

 tion of the ingredients, viz., 20 drops of essential oil of oranges 

 to 30 grms. of liquid vaseline. A 25 per cent, solution of sul- 

 phate of potash mixed with oil of cassia has also been recom- 

 mended. 



PORTCHINSKY (I. A.). 40M0BAfl MXXV (Musci?ia stahxlans. 

 Fall.); EH 31IAqEIlIE ^Jfl ME.IOBliKA 11 ElO X03aiiCTBA 

 II OTnOlHEllIE EH Kh KOMHATHOli MAXB [The domestic 

 fly {Muscina stahulans, Fall.) ; its importance to man and his 

 household, and its relations with the house flv (Miisca 

 domestica)\—Tn' ]\hl EIOPO 110 ailTOMOJOrill A qenaro 

 KoviiiTeTa r.iaBiiaro .VnpaRienia Sevi.ievcTpoiicTBa h SeM.ie^'kia 

 [Memoirs of the Bureau of Entomology of the Scientific 

 Committee of the Central Board of Lancf Administration and 

 Agriculture], x, no. 1, 39 pp., 32 figs. St. Petersburg, 1913. 



The author states that Muscina stahulans, Fin., is a fly which 

 is really very little known and has not been greatly studied, 

 although it is a very important factor in the spread of various 

 diseases; in this respect it is less dangerous than Musca domestica, 

 but only because it appears in relatively small numbers in human 

 dwellings. Nevertheless the habits of this fly as described by 

 the author point to the injurious role played by it in human 

 household economy. It is capable of breeding in various substances 

 found in nature and only single individuals are as a rule met with 

 in human habitations; otherwise the state of war which exists 

 iDetween this fly and Musca domestica in the larval stage, which 

 was proved quite unexpectedly by the author's studies, would 

 have led to the total extermination of the latter fly and to its 

 substitution by the more dangerous and injurious Muscina 

 stahulans. 



The experiments of the author on the relations between the 

 larvae of these two flies were rendered more difficult by the fact 

 that Muscina stahulans is very unwilling to lay its eo-o-s in 

 captivity. Out of a number of female flies whose ovaries' con- 

 tained ripe, fertilised eggs only few actually oviposited, most of 

 them dying before this was accomplished. In this M. stahulans 

 differs_ sharply from Musca domestica. The larvae of these two 

 flies live but a very short time peacefully together. Having 

 completed the second stage, the larvae of M. Stahulans follow and 

 attack the larvae of M. domestica and very soon exterminate all 

 that happen to be living along with them. The author describes 

 some interesting observations made by him, in which quite young 

 larvae of M. stahulans becoming sensible of the presence of a 

 full-grown larva of M. domestica immediately attacked it, twist- 

 ing round and holding on to it by means of the small hooks 

 situated on the under surface of their bodies, striking their victim 



