86 



in a particular area, the first necessity is plenty of moisture and a higk 

 degree of humidity. In a warm, dry climate amoebic cysts have little 

 chance of survival, notwithstanding an abundance of flies. Dysenteric 

 bacilli, on the contrary, must be capable of withstanding a much greater 

 degree of dryness to account for the occurrence of bacillary dysentery 

 in hot climates. 



Howard (C. W.). Insect Transmission of Infectious Anemia of Horses.. 



— Jl. Parasitology, Urbana, III, iv, no. 2, December 1917, 

 pp. 70-79 



During the past ten years many different investigations have been 

 made on the nature of the transmission of swamp fever or infectious 

 anaemia of horses, a disease which is widely distributed, but not 

 restricted, as its name would imply, to low-lying, wet land. Since 

 it attacks equines only, etiological investigations are hindered by the 

 impossibility of using small laboratory animals experimentally. 



Research seems to show that infection does not take place through 

 the digestive or respiratory organs, but through the skin, the infective 

 agents being neither ticks, bots, mosquitos, nor Tabanids, but. 

 Stomoxys calcitrans (biting stable fly), though it has not yet been 

 proved that these insects are the usual or only carriers of the disease. 



Moll (A. M.). Animal Parasites of Rats at Madison, Wisconsin. — JL 



Parasitology, TJrbana, III., iv, no. 2, December 1917, pp. 89-90. 



An examination of twenty-five examples of the so-called brown rat,. 

 Mils norvegicus, has shown that they all carried internal and external 

 parasites, but in no case was any blood parasite found. 



The insect parasites found were : — Polyplax {Hae?natopinus) spimi- 

 losiis, Burm. (rat louse), which transmits an apparently non- 

 pathogenic protozoan parasite, Trypanosoma letvisi, from one rat to- 

 another ; Ctenocephalus canis, Curtis (dog flea), which is the- 

 intermediate host of the tapeworm, Dipylidium canimmi ; Cerato- 

 phyllus fasciakts, Bosc. (rat flea), which completes its life-cycle- 

 on the rat only, but bites man in preference to rats when possible, 

 thus becoming an important factor in plague-infested localities ; 

 and Laelaps agilis, Koch, a mite that rarely attaches itself to- 

 man or to domestic animals and is consequently of little economic 

 importance. 



Dyar (H. G.) & Knab (F.). New American Mosquitoes (Diptera, 

 Culicidae). — Insecutor Inscitiae Menstnms, Washington, D.C., v, 

 nos, 10-12, October-December 1917, pp. 165-169. 



The mosquitos dealt with in this paper are Aedes zoosophus, sp. n.,. 

 from Texas, apparently allied to A. fluviatilis, Lutz, and probably 

 breeding, as that species does, in rock-holes along streams ; A. gonimus,, 

 sp. n., from Texas, a fierce biter ; A. niphadopsis, sp. n., from Utah ; 

 A. epinolns, D. & K., a male from Ecuador, previously described from 

 females from Peru ; and A. innvitus, sp. n.. from Greenland, which is. 

 possibly identical with Culex nigripes, Zett., from Lapland. 



