84 



chemical strength, the potential hydrogen ion or equivalent being 

 equal to that in a 2 per cent, (by weight) solution of butyric acid. 

 The calcium hydroxide solution was saturated at 20° C. 



In the case of sodium carbonate, which was the most attractive, 

 the moistened bran baits tested before exposure were neutral to 

 phenolphthalein but, after six hours, the acidity measured by the 

 same indicator was practically equal to the alkalinity obtained by 

 the dosage used in the sodium carbonate units. It is possible that the 

 carbonic acid in the sodium carbonate becomes completely liberated, 

 and this free carbonic acid in the moist bran bait may account for the 

 fact that the highest percentage of egg'i was obtained in these cases. 

 The authors consider this a confirmation of the results obtained with 

 carbon dioxide in the previous observations [loc. cit.]. Sodium 

 hydroxide is moderately attractive, its effect depending on the 

 liberation of carbon dioxide as a result of a sequence of changes. 



The sodium ion present in sodium sulphate, sodium carbonate 

 and sodium hydroxide is not a repellent to house-fly oviposition, and 

 its presence in some salt combinations may be moderately attractive. 

 Gravid house-flies appear to be indifferent to the presence of the organic 

 bases, grain alcohol and glycerine, as well as mixed compound lactic 

 acid. Hydrochloric and sulphuric acids appear to be moderate 

 repellents. 



The house-fly {Musca domestica) is attracted for oviposition by 

 decaying organic matter in proportion to the amount of carbonic 

 and acetic acids liberated in the process of fermentation ; this may 

 also account for its preference for decaying vegetable rather than 

 animal matter. The predisposition for these two acids may also 

 explain the affinity of the house-fly for human environments generally 

 and particularly dwelling-houses and stables. 



Maxwell (J. P.). Filariasis in China. — Philippine Jl. Sci., Manila, 

 xix, no. 3, September 1921, pp. 257-327, 24 plates, 4 charts, 

 1 map. [Received 7th February 1922.] 



The greater part of this paper is devoted to filarial diseases from the 

 clinical point of view ; but some account of the filariae, their life- 

 history and transmission is also given. 



Filariasis in man in China is caused almost exclusively by Filaria 

 bancrofti, transmitted by mosquitos [R.A.E., B, viii, 115]. Culex 

 fatigans and C. pipiens are both common, though it is possible that 

 there are other Culicids that are potential carriers. 



All classes and ages are subject to the disease, but in China women 

 are much less often infected than men, while labourers are more often 

 infected than those leading a sedentary life. Probably dress, par- 

 ticularly the amount of leg that is normally bare, contributes to this. 



Craighead (E. M.). Observations on certain Siphonaptera. — Ent. 

 News, Philadelphia, xxxii, no. 10, December 1921, pp. 303-308. 



This paper describes observations on Ctenocephalus canis, Curt., 

 C.felis, Bch., and Ceratophyllus fasciatus, Bosc. 



It was proved that no larvae survive in a temperature of 70° F. 

 or more without moisture A table is given showing the result of 

 moisture and temperature on the hatching of the eggs. The larvae 

 thrive best when fed on adult flea faeces. Eggs hatched in an average 

 of 4 days, the larval stage occupied 14 days, the pupal 4 days, and 



