70 



is very remarkable. From the moment of emergence from the egg 

 they may be kept in absolutely dry surroundings without food for 

 more than three weeks. Older larvae can easily resist starvation 

 for a whole month, and the author says that he has kept a larva 

 of .4, luteola under these conditions for GO days. If the larvae 

 are fed daily their total life is from 14 to 15 days. They moult 

 twice, once about the second and again about the sixth day. If 

 the feeding is interrupted by long periods of starvation the 

 development is much delayed. In the case of A. luteola, feeding 

 once a week, or at intervals of 10 days, postponed the nymphal 

 stage for 2h months ; a similar effect is produced on the period of 

 moulting. If fed by day, and also after several days of starva- 

 tion, the larvae lose their usual nocturnal habits. 



When buried in the soil the larvae exhibit a curious sensibility 

 tu heat. If the surrounding medium be slightly warmed, the 

 larvae wake up, become very active and seek the source of heat; 

 this fact can be easily observed in a glass vessel. It is apparently 

 by means of this thermotropism tliat the parasites, dispersed in 

 the soil, are guided to their host. This sensibility to heat is only 

 manifested by larvae without food ; when fed they are apparently 

 insensible to a rise in temperature. 



XicoLLE (C. X.), Blaizot (L.) & CoxsEiL (E.). Etiologie de la 

 Fievre Recurrente, son mode de transmission par les poux. 

 [Etiology of Recurrent Eever and tlie mode of its trans- 

 mission bv Lice.] — Ann. hisf. Pasteur, 25th Marcli 191:!. 

 pp. 204-225. 



The researches recorded in this paper were undertaken by the 

 authors during an epidemic which raged in Tunis and its neigh- 

 bourhood from February to August, 1912. Recurrent fever is 

 rare in Tunis ; its very special characters do not permit the supposi- 

 tion that it has been overlooked. It was first recognised in the 

 country by Lafforgue in 1903 amongst the natives of the district 

 of Zaghouan ; again by Conseil in the Mussulman hospital in 

 Tunis in 1907 ; and a large number of cases were observed by 

 Blaizot aiul Gobert at the phosphate mines of Redeyef in South 

 Tunis, several cases from this source reaching Tunis itself. The 

 disease has been known in Algeria at least since 1866. The 

 various epidemics which have been observed in Tunis have all 

 been traced to Tripoli and immigrants therefrom. 



The disease has been known for a long time under the name of 

 iyphus, and the authors consider they are able to show a like 

 origin for it and for exanthematous typhus. In the native tongue 

 both appear to be confounded in the name " m'ard qmel " (tlie 

 louse disease), which Cardaliaguet has proposed for exanthematous 

 typhus. The mere spread of the term should, in itself, act as a 

 prophylactic. 



The authors discuss at some length early opinions on the 

 etiology of recurrent fever and the attempts that have been made 

 to incriminate bugs and fleas. They examine the evidence and 

 endeavour to show that it is entirely unsatisfactory. Similarly 

 other authorities have sought to fix the responsibility for the trans- 

 mission of the infection upon the bite of the bodv louse, the 



