177 



enemies of mosqiiitos and he considers that tliey should he culti- 

 vated and utilised for mosquito reduction. He says tliat hats are 

 prohahly immune from the bite of a mosquito, firstly because of 

 tlie peculiar formation of the hair covering' their bodies and 

 secondly because of their peculiar odour, lie points out that 

 bats are remarkably free from disease and that this is shown by 

 the fact that although they live in ca\es in vast numbers, touch- 

 ing one another and even hangino" to one another, yet men 

 engaged in collecting bat guano very rarely find a dead bat. 



The author has made observations in a hunter's cabin 10 miles 

 from San Antonio (Texas) where bats were congregating. He 

 spread large white sheets on the floor about 4 o'clock in the morning 

 and so prepared the roosting places in the hut that bats could not 

 roost except above the sheets. The bats were counted in and 

 counted out and the guano collected, witli the result that the 

 latter averaged 26 pieces to each bat. From this and other data 

 similarly obtained he estimates that a structure large enough to 

 hold 5()(),00() bats would cost considerably less than £2,400 and 

 that they would yield in a year 20|- tons of guano of an average 

 value of £121 10.s\ lie then proceeded to construct a bat roost 

 from his own design in a place near San Antonio notorious for 

 mosquitos. The roost was finished in April 1911; in August he 

 estimated that several hundred bats required 20 minutes flying 

 in one constant stream to enter the roost. In 1912 the numbers 

 in the roost were so great that it took tliem several hours to come 

 out. A short time before making this communication to the 

 Institute he made inquiries of the heads of 14 families and all 

 declared that the mosquitos last year were very much less than 

 the year before and that fever had almost vanished. Others said 

 that before the roosts were erected the cattle were very thin and 

 poor, in spite of the good food, which was attributed to worry by 

 mosquitos ; and the workmen engaged on irrigation w^ork close by 

 previously complained of being sometimes driven away from 

 their work by the mosquitos, but were now scarcely troubled by 

 them. The duck-hunters also remarked that the mosquitos had 

 greatly diminished. The author concludes from these observa- 

 tions that it is not only commercially, but hygienically, profitable 

 to cultivate bats. 



Laveran (A.) & Franciiini (G.). Infections experimentales de la 

 souris par Jlerpetomona^ ctenocephaJi. [The experimental 

 infection of mice with Herpetomnnas cfrnocej^Jinli.] — C. R. 

 hehd. Acad. Sci., Paris, clvii, no. 9, 1st Sept. 1913, pp. 423- 

 426. 



The authors state that tlie number of Ctenocephalvs ca7iis 

 infected with Herpetomonas varies considerably, according to the 

 place of origin of the fleas. Of 23 fleas taken from dogs in a 

 kennel at the Institut Pasteur 12 were infected, whereas of 30 

 fleas taken from young dogs recently placed in the same kennel 

 none were infected. In 1912 Lafont recorded that if mice were 

 inoculated with trypanosomids from the intestine of Conoi-hinvs. 



