64 



probably to all newly-hatched individuals. Bugs which are not killed 

 by the infecting meal, are capable of carrying B. pestis and reinfecting 

 mice after a period of 48 days' starvation. The development of 

 B. ]}€stis within the crop of bugs differs generally from that which 

 takes place in the stomach of the flea, in respect of its slower and looser 

 growth, this limitation of activity being accompanied by, and possibly 

 being due to, the preservation of the structural character of the blood 

 for many days after its ingestion into the crop. Mouth infection, 

 when not caused by accidental or other injury to the bug while feeding, 

 may be due to interruption followed by a second attempt. 

 A bibliography of six works is given. 



■OuiTERAS (G. M.). Plague in Havana. — JL Amer. Med. Assoc, Chicago, 

 Lxiv, no. 1, 2nd January 1915, pp. 29-34. 



For fumigating small spaces such as rat-holes, runs and caves, 

 Dr. Hugo Roberts, Chief Quarantine Officer of Cuba, has devised the 

 following apparatus : — a wooden box, 12 by 4 inches, is made with 

 a false bottom with two circular openings into which are inserted two 

 1,000 cc. bottles with rubber stoppers. Each of these is perforated 

 with two openings to permit the passage of the glass tubing connecting 

 the two bottles and each in turn to the rubber bulb and the outlet 

 tube, to which, for convenience, a glass nozzle may be attached. 

 The bottle to which the rubber bulb is connected, is charged with 

 sulphuric acid diluted with two or three times its volume of water. 

 The bottle to which the rubber tube and glass nozzle is attached, is 

 charged with powdered potassium cyanide. By means of pressure on 

 the bulb the acid solution is forced into the bottle containing the 

 cyanide. The hydrocyanic acid gas evolved passes out of the glass 

 nozzle, which has previously been inserted into a rat-hole, the open 

 space around the nozzle having been sealed with a small quantity of 

 cement mortar. The box is fitted with a movable handle which serves 

 for carrying, facilitates the removal of the bottles for recharging, and 

 prevents kinks in the exit tube by serving as a rest for it. The 

 size described is suitable for small rat-holes ; for larger holes bottles 

 of 5,000 cc. capacity are used, and a bicycle pump replaces the bulb. 

 The small apparatus is charged with 150 grammes of powdered 

 commercial potassium cyanide and about 300 grammes of crude 

 sulphuric acid diluted with three times its weight of water. This is 

 calculated to yield 400 cubic feet of 1-6 per cent, hydrocyanic acid 

 gas. The apparatus is now extensively used in the anti-rat campaign 

 in Havana. 



Pasqualis (L.). Venezia e le Zanzare. [Venice and mosquitos.] — 

 L'Amico del Contadino, Udine, xxi, no. 1, 2nd January 1915, p. 4. 



This article is part of a larger one dealing, in popular form, w^th 

 l)ird protection from an agricultural point of view. It seems that so 

 long as swallows are to be found in Venice there is no annoyance 

 from mosquitos, but when the birds migrate late in July these insects 

 appear in swarms. 



